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Sample records for cells delays cell

  1. Delay estimation for CMOS functional cells

    DEFF Research Database (Denmark)

    Madsen, Jan

    1991-01-01

    Presents a new RC tree network model for delay estimation of CMOS functional cells. The model is able to reflect topological changes within a cell, which is of particular interest when doing performance driven layout synthesis. Further, a set of algorithms to perform worst case analysis on arbitr...... arbitrary CMOS functional cells using the proposed delay model, is presented. Both model and algorithms have been implemented as a part of a cell compiler (CELLO) working in an experimental silicon compiler environment.......Presents a new RC tree network model for delay estimation of CMOS functional cells. The model is able to reflect topological changes within a cell, which is of particular interest when doing performance driven layout synthesis. Further, a set of algorithms to perform worst case analysis on...

  2. Cell probing by delayed luminescence

    Science.gov (United States)

    Musumeci, Francesco; Ballerini, Monica; Baroni, Giuliana; Costato, Michele; Ferraro, Lorenzo; Milani, Marziale; Scordino, Agata; Triglia, Antonio

    1999-05-01

    Delayed luminescence (D.L.) is a measure that provides important information on biological systems fields, structures and activities, by counting impinging and emitted photons. Many recent experimental works have shown the existence of a close connection, sometimes analytically expressed between the biological state of the system and D.L. parameters. Our investigations aim to show that D.L. is a workable analytical technique covering a large number of disciplinary fields, from agriculture to pollution control and from medical diagnostics to food quality control. The authors have conducted systematic research about D.L. from unicellular alga Acetabularia acetabulum to Saccharomyces cerevisiae yeast cultures and about more complex systems such as Soya seed (Glycine max, L.) and its dependence on sample preparation, history, intracellular signaling, metabolism and pollutant presence. We will discuss the most relevant results together with theoretical considerations on the basic interaction at work between biological systems and electromagnetic fields.

  3. BOLD delay times using group delay in sickle cell disease

    Science.gov (United States)

    Coloigner, Julie; Vu, Chau; Bush, Adam; Borzage, Matt; Rajagopalan, Vidya; Lepore, Natasha; Wood, John

    2016-03-01

    Sickle cell disease (SCD) is an inherited blood disorder that effects red blood cells, which can lead to vasoocclusion, ischemia and infarct. This disease often results in neurological damage and strokes, leading to morbidity and mortality. Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique for measuring and mapping the brain activity. Blood Oxygenation Level-Dependent (BOLD) signals contain also information about the neurovascular coupling, vascular reactivity, oxygenation and blood propagation. Temporal relationship between BOLD fluctuations in different parts of the brain provides also a mean to investigate the blood delay information. We used the induced desaturation as a label to profile transit times through different brain areas, reflecting oxygen utilization of tissue. In this study, we aimed to compare blood flow propagation delay times between these patients and healthy subjects in areas vascularized by anterior, middle and posterior cerebral arteries. In a group comparison analysis with control subjects, BOLD changes in these areas were found to be almost simultaneous and shorter in the SCD patients, because of their increased brain blood flow. Secondly, the analysis of a patient with a stenosis on the anterior cerebral artery indicated that signal of the area vascularized by this artery lagged the MCA signal. These findings suggest that sickle cell disease causes blood propagation modifications, and that these changes could be used as a biomarker of vascular damage.

  4. Delayed type hypersensitivity to allogeneic mouse epidermal cell antigens, 2

    International Nuclear Information System (INIS)

    A low dose of ultraviolet B radiation impairs the effectiveness of epidermal cell antigens. We studied the effect of ultraviolet B radiation on the delayed type hypersensitivity induced by allogeneic epidermal cell antigen. The delayed type hypersensitivity response was assayed by footpad swelling in mice. When epidermal cells were exposed to ultraviolet B radiation (660 J/m2), their ability to induce T cells of delayed type hypersensitivity activation was markedly inhibited in any combination of recipient mice and allogeneic epidermal cells. The effect of ultraviolet B radiation on epidermal cells was observed before immunization and challenge. Ultraviolet B treated epidermal cells did not induce suppressor T cells in mice. These results indicate that ultraviolet B radiation destroys the antigenicity of epidermal cells. (author)

  5. Cell cycle delays in synchronized cell populations following irradiation with heavy ions

    International Nuclear Information System (INIS)

    Mammalian cells subjected to irradiation with heavy ions were investigated for cell cycle delays. The ions used for this purpose included Ne ions in the LET range of 400 keV/μm just as well as uranium ions of 16225 keV/μm. The qualitative changes in cell cycle progression seen after irradiation with Ne ions (400 keV/μm) were similar to those observed in connection with X-rays. Following irradiation with extremely heavy ions (lead, uranium) the majority of cells were even at 45 hours still found to be in the S phase or G2M phase of the first cycle. The delay cross section 'σ-delay' was introduced as a quantity that would permit quantitative comparisons to be carried out between the changes in cell progression and other effects of radiation. In order to evaluate the influence of the number of hits on the radiation effect observed, the size of the cell nucleus was precisely determined with reference to the cycle phase and local cell density. A model to simulate those delay effects was designed in such a way that account is taken of this probability of hit and that the results can be extrapolated from the delay effects after X-irradiation. On the basis of the various probabilities of hit for cells at different cycle stages a model was developed to ascertain the intensified effect following fractionated irradiation with heavy ions. (orig./MG)

  6. Case reports: delayed hemolytic transfusion reaction in sickle cell disease.

    Science.gov (United States)

    Syed, S K; Sears, D A; Werch, J B; Udden, M M; Milam, J D

    1996-10-01

    This article reports the details of delayed hemolytic transfusion reactions in four patients with sickle cell disease. These cases demonstrate the characteristics of the reactions, the significant risks involved, and the principles useful in diagnosis and treatment. Patients with sickle cell disease are at particular risk for delayed hemolytic transfusion reactions because they may be transfused at intervals over many years; they frequently form alloantibodies because of antigenic differences from the donor population; and they may receive emergency care in different hospitals where transfusion records are not available. In addition, exchange transfusions, which are often used for patients with sickle cell disease and which were given in three of these cases, raise the risks through increased exposure to foreign erythrocyte antigens and through an increased volume of erythrocytes susceptible to hemolysis. It was concluded that the hazards of these transfusion reactions justify preventive measures, such as extended erythrocyte phenotyping of patients with sickle cell disease and extended phenotypic matching of transfused cells. PMID:8853066

  7. Compact cascadable gm-C all-pass true time delay cell with reduced delay variation over frequency

    NARCIS (Netherlands)

    Garakoui, Seyed Kasra; Klumperink, Eric A.M.; Nauta, Bram; Vliet, van Frank E.

    2015-01-01

    At low-GHz frequencies, analog time-delay cells realized by LC delay lines or transmission lines are unpractical in CMOS, due to their large size. As an alternative, delays can be approximated by all-pass filters exploiting transconductors and capacitors (g m -C filters). This paper presents an easi

  8. All delays before radiotherapy risk progression of Merkel cell carcinoma

    International Nuclear Information System (INIS)

    Prolonged waiting times for radiotherapy have resulted in many centres assigning priorities to various patient or diagnostic groups. A high risk of progression on a waiting list is one factor that would reasonably influence the priority. The present descriptive study of 27 patients with Merkel cell carcinoma (MCC) found that a median wait of 24 days for radiotherapy is associated with a high risk of progression. Eleven (41%) of 27 patients developed progressive disease, including five (45%) of 11 patients waiting for adjuvant radiotherapy. Patients treated adjuvantly also had longer waiting times prior to their initial radiotherapy consultation (median 41 days), which may have contributed to the rate of progression. Merkel cell carcinoma is an aggressive but curable malignancy and appropriate management should include efforts to minimize all potential delays prior to the commencement of radiotherapy. Copyright (2004) Blackwell Science Pty Ltd

  9. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    International Nuclear Information System (INIS)

    Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of

  10. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    Directory of Open Access Journals (Sweden)

    Esser Norbert

    2011-06-01

    Full Text Available Abstract Background and Purpose Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR. Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Materials and methods Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF and fibroblast growth factor-2 (FGF-2. Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. Results SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Conclusions Our results suggest the importance of delayed

  11. ACE2 is required for daughter cell-specific G1 delay in Saccharomyces cerevisiae

    OpenAIRE

    Laabs, Tracy L.; Markwardt, David D.; Slattery, Matthew G.; Newcomb, Laura L.; Stillman, David J.; Heideman, Warren

    2003-01-01

    Saccharomyces cerevisiae cells reproduce by budding to yield a mother cell and a smaller daughter cell. Although both mother and daughter begin G1 simultaneously, the mother cell progresses through G1 more rapidly. Daughter cell G1 delay has long been thought to be due to a requirement for attaining a certain critical cell size before passing the commitment point in the cell cycle known as START. We present an alternative model in which the daughter cell-specific Ace2 ...

  12. Delayed luminescence to monitor programmed cell death induced by berberine on thyroid cancer cells

    Science.gov (United States)

    Scordino, Agata; Campisi, Agata; Grasso, Rosaria; Bonfanti, Roberta; Gulino, Marisa; Iauk, Liliana; Parenti, Rosalba; Musumeci, Francesco

    2014-11-01

    Correlation between apoptosis and UVA-induced ultraweak photon emission delayed luminescence (DL) from tumor thyroid cell lines was investigated. In particular, the effects of berberine, an alkaloid that has been reported to have anticancer activities, on two cancer cell lines were studied. The FTC-133 and 8305C cell lines, as representative of follicular and anaplastic thyroid human cancer, respectively, were chosen. The results show that berberine is able to arrest cell cycle and activate apoptotic pathway as shown in both cell lines by deoxyribonucleic acid fragmentation, caspase-3 cleavage, p53 and p27 protein overexpression. In parallel, changes in DL spectral components after berberine treatment support the hypothesis that DL from human cells originates mainly from mitochondria, since berberine acts especially at the mitochondrial level. The decrease of DL blue component for both cell lines could be related to the decrease of intra-mitochondrial nicotinamide adenine dinucleotide and may be a hallmark of induced apoptosis. In contrast, the response in the red spectral range is different for the two cell lines and may be ascribed to a different iron homeostasis.

  13. Radioresistance of cells responsible for delayed hypersensitivity reactions in the mouse

    International Nuclear Information System (INIS)

    The cells responsible for delayed hypersensitivity reactivity in the mouse act in a radioresistant fashion only if such irradiated cells are injected directly into the site of antigen challenge. Intravenous transfer of irradiated, primed spleen cells does not achieve a transfer of sensitivity to show delayed type hypersensitivity reactions. Transfer of sensitivity by the intravenous route can be effected by injection of non-irradiated spleen cells from primed mice. (U.S.)

  14. Qualitative Properties in a More General Delayed Hematopoietic Stem Cells Model*

    OpenAIRE

    Aziz-Alaoui M. A.; Yafia R.

    2013-01-01

    In this paper, we consider a more general model describing the dynamics of Hematopoietic Stem Cells (HSC) model with one delay. Its dynamics are studied in terms of local stability and Hopf bifurcation. We prove the existence of the possible steady state and their stability with respect to the time delay and without delay. We show that a sequence of Hopf bifurcations occur at the positive steady state as the delay crosses some critical values. We illustrate our results by some numerical ...

  15. An efficient current-based logic cell model for crosstalk delay analysis

    Science.gov (United States)

    Nazarian, Shahin; Das, Debasish

    2013-04-01

    Logic cell modelling is an important component in the analysis and design of CMOS integrated circuits, mostly due to nonlinear behaviour of CMOS cells with respect to the voltage signal at their input and output pins. A current-based model for CMOS logic cells is presented, which can be used for effective crosstalk noise and delta delay analysis in CMOS VLSI circuits. Existing current source models are expensive and need a new set of Spice-based characterisation, which is not compatible with typical EDA tools. In this article we present Imodel, a simple nonlinear logic cell model that can be derived from the typical cell libraries such as NLDM, with accuracy much higher than NLDM-based cell delay models. In fact, our experiments show an average error of 3% compared to Spice. This level of accuracy comes with a maximum runtime penalty of 19% compared to NLDM-based cell delay models on medium-sized industrial designs.

  16. Delayed effects of cold atmospheric plasma on vascular cells

    NARCIS (Netherlands)

    Stoffels, Eva; Roks, Anton J. M.; Deelmm, Leo E.

    2008-01-01

    We investigated the long-term behaviour of vascular cells (endothelial and smooth muscle) after exposure to a cold atmospheric plasma source. The cells were treated through a gas-permeable membrane, in order to simulate intravenous treatment with a gas plasma-filled catheter. Such indirect treatment

  17. Time delay and noise explaining the behaviour of the cell growth in fermentation process

    Energy Technology Data Exchange (ETDEWEB)

    Ayuobi, Tawfiqullah; Rosli, Norhayati [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Pahang (Malaysia); Bahar, Arifah [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Salleh, Madihah Md [Department of Biotechnology Industry, Faculty of Biosciences and Bioengineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2015-02-03

    This paper proposes to investigate the interplay between time delay and external noise in explaining the behaviour of the microbial growth in batch fermentation process. Time delay and noise are modelled jointly via stochastic delay differential equations (SDDEs). The typical behaviour of cell concentration in batch fermentation process under this model is investigated. Milstein scheme is applied for solving this model numerically. Simulation results illustrate the effects of time delay and external noise in explaining the lag and stationary phases, respectively for the cell growth of fermentation process.

  18. Time delay and noise explaining the behaviour of the cell growth in fermentation process

    Science.gov (United States)

    Ayuobi, Tawfiqullah; Rosli, Norhayati; Bahar, Arifah; Salleh, Madihah Md

    2015-02-01

    This paper proposes to investigate the interplay between time delay and external noise in explaining the behaviour of the microbial growth in batch fermentation process. Time delay and noise are modelled jointly via stochastic delay differential equations (SDDEs). The typical behaviour of cell concentration in batch fermentation process under this model is investigated. Milstein scheme is applied for solving this model numerically. Simulation results illustrate the effects of time delay and external noise in explaining the lag and stationary phases, respectively for the cell growth of fermentation process.

  19. Bifurcation analysis of HIV-1 infection model with cell-to-cell transmission and immune response delay.

    Science.gov (United States)

    Xu, Jinhu; Zhou, Yicang

    2016-04-01

    A within-host viral infection model with both virus-to-cell and cell-to-cell transmissions and time delay in immune response is investigated. Mathematical analysis shows that delay may destabilize the infected steady state and lead to Hopf bifurcation. Moreover, the direction of the Hopf bifurcation and the stability of the periodic solutions are investigated by normal form and center manifold theory. Numerical simulations are done to explore the rich dynamics, including stability switches, Hopf bifurcations, and chaotic oscillations. PMID:27105992

  20. A case of delayed hemolytic transfusion reaction in sickle cell disease patient

    Science.gov (United States)

    Dogra, Ashu; Sidhu, Meena

    2016-01-01

    Sickle cell disease (SCD) is autosomal recessive, genetically transmitted hemoglobinopathy responsible for considerable morbidity and mortality. It is prevalent in many parts of India including Central India, where the prevalence in different communities has ranged from 9.4% to 22%. Perioperative management may include transfusion of red blood cells. Hemolytic transfusion reactions can occur, and these can be either acute or delayed. We present a case of delayed hemolytic transfusion reaction in a patient with SCD. PMID:27605854

  1. Delayed BMP4 exposure increases germ cell differentiation in mouse embryonic stem cells.

    Science.gov (United States)

    Talaei-Khozani, Tahereh; Zarei Fard, Nehleh; Bahmanpour, Soghra; Jaberipour, Mansoureh; Hosseini, Ahmah; Esmaeilpour, Tahereh

    2014-01-01

    Fate mapping studies have revealed that bone morphogenetic protein 4 (BMP4) signaling has a key role in segregation of primordial germ cells from proximal epiblast. Adding BMP4 to the culture media of embryonic stem (ES) cells could induce expression of germ cell markers; however, to provide a desired number of germ cells has remained a challenge. In the current study, we intended to establish an in vitro system to obtain reliable germ cells derived from ES cells. Differentiation was induced in ES cells via embryoid body (EB) and monolayer culture system. Cells were cultured with BMP4 from the beginning (++BMP4) or after 48 hours (+BMP4) of culturing for five days. The cultures were assessed for alkaline phosphatase (ALP) activity, expression of Oct4, Mvh and c-kit. In EB culture protocol, the expression of Mvh, Oct4 and ALP activity significantly increased in +BMP4 culture condition, but a significant down-regulation in the expression of germ cell markers was shown in ++BMP4 condition compared with the control group. Parallel differentiation experiments using monolayer culture system indicated the number of putative germ cells did not change. In the current study, we compared two differentiation methods (EB and monolayer) to achieve an optimal germ cell production. The EBs with a short exposure time period to BMP4, showing typical characteristics of germ cells. Therefore, our approach provides a strategy for the production of germline cells from ES cells. PMID:24969978

  2. Binary Optical True-Time Delay Based on the White Cell: Design and Demonstration

    Science.gov (United States)

    Anderson, Betty Lise; Rabb, David J.; Warnky, Carolyn M.; Abou-Galala, Feras

    2006-04-01

    An optical true-time delay device that uses a binary counting system in a modified White cell is demonstrated. The switching engine uses four spherical mirrors and a three-state digital micromirror array. The delay part, as designed, provides 6 bits of delay ranging from 78 ps to 5 ns, using a combination of dielectric blocks for short delays and lens trains for longer ones. Long lens trains are folded for compactness. The authors describe the design and demonstrate two of the 6 bits of delays experimentally. Delays were accurate to within the measurement resolution of 1.25 ps. The insertion loss varied from 3.1-5.2 dB, depending on delay. It was found that the micromirrors do not contribute significantly to the loss.

  3. Expression of Delayed Cell Death and DNA Repair in Human Epithelial Cell Lines Following Exposure to Ultraviolet Radiation

    International Nuclear Information System (INIS)

    The long term effects of UVA and UVB have been investigated using two human epithelial cell lines, HTori-3 (a human thyroid epithelial cell line) and 340 RPE-T53 (a human retinal pigment epithelial cell line). There was a marked difference in clonogenic survival following exposure between the two cell lines. DNA repair studies were undertaken using ara-C treatment. Ara-C administered immediately after UVB exposure, reduced survival in both cell lines indicating that DNA repair was inhibited. The plating efficiency, as an index of delayed cell death of both cell lines measured up to 20 population doublings following exposure to UV was reduced in a dose dependent manner after exposure to UVB but not to UVA. (author)

  4. S-phase delay in human hepatocellular carcinoma cells induced by overexpression of integrin β1

    Institute of Scientific and Technical Information of China (English)

    Yu-Long Liang; Ting-Wen Lei; Heng Wu; Jian-Min Sn; Li-Ying Wang; Qun-Ying Lei; Xi-Liang Zha

    2003-01-01

    AIM:To clarify the mechanisms of integrin overexpression in negatively regulating the cell cycle control of hepatocellular carcinoma cells SMMC-7721.METHODS: The cell cycle pattern was determined by flow cytometry. The mRNA and protein expression levels were assayed by RT-PCR and Western blot, respectively. Stable transfection was performed by Lipofectamine 2000 reagent,and cells were screened by G418.RESULTS: Overexpression of α5β1 or β1 integrin induced S-phase delay in SMMC-7721 cells, and this delay was possibly due to the accumulation of cyclin-dependent kinase inhibitors (CKIs) p21cip1 and p27kip1. The decrease of protein kinase B (PKB) phosphorylation was present in this signaling pathway, but focal adhesion kinase (FAK) was not involved.When phosphorylation of PKB was solely blocked by wortmannin, p27kip1 protein level was increased. Moreover,S-phase delay was recurred when attachment of the parental SMMC-7721 cells was inhibited by the preparation of polyHEME, and this cell cycle pattern was similar to that of β1-7721 or α5β1-7721 cells.CONCLUSION: S-phase delay induced by overexpression of integrin β1 subunit is attributed to the decrease of PKB phosphorylation and subsequent increases of p21cip1 and p27kip1 proteins, and may be involved in the unoccupied α5β1because of lack of its ligands.

  5. Adaptation to alkalosis induces cell cycle delay and apoptosis in cortical collecting duct cells: role of Aquaporin-2.

    Science.gov (United States)

    Rivarola, Valeria; Flamenco, Pilar; Melamud, Luciana; Galizia, Luciano; Ford, Paula; Capurro, Claudia

    2010-08-01

    Collecting ducts (CD) not only constitute the final site for regulating urine concentration by increasing apical membrane Aquaporin-2 (AQP2) expression, but are also essential for the control of acid-base status. The aim of this work was to examine, in renal cells, the effects of chronic alkalosis on cell growth/death as well as to define whether AQP2 expression plays any role during this adaptation. Two CD cell lines were used: WT- (not expressing AQPs) and AQP2-RCCD(1) (expressing apical AQP2). Our results showed that AQP2 expression per se accelerates cell proliferation by an increase in cell cycle progression. Chronic alkalosis induced, in both cells lines, a time-dependent reduction in cell growth. Even more, cell cycle movement, assessed by 5-bromodeoxyuridine pulse-chase and propidium iodide analyses, revealed a G2/M phase cell accumulation associated with longer S- and G2/M-transit times. This G2/M arrest is paralleled with changes consistent with apoptosis. All these effects appeared 24 h before and were always more pronounced in cells expressing AQP2. Moreover, in AQP2-expressing cells, part of the observed alkalosis cell growth decrease is explained by AQP2 protein down-regulation. We conclude that in CD cells alkalosis causes a reduction in cell growth by cell cycle delay that triggers apoptosis as an adaptive reaction to this environment stress. Since cell volume changes are prerequisite for the initiation of cell proliferation or apoptosis, we propose that AQP2 expression facilitates cell swelling or shrinkage leading to the activation of channels necessary to the control of these processes. PMID:20432437

  6. Interaction of hyperthermia and radiation on the induction of division delay in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The mitotic selection procedure for cell cycle analysis was used in the investigation of the interaction of hyperthermia and ionizing radiation on the induction and duration of division delay in Chinese hamster ovary cells. Hyperthermia (immersion in a 45 degrees C water bath) produced a blockade of cell cycle progression with a transition point in late G2-early M, approximately at the X-ray transition point (35 min prior to selection). The duration of division delay for heated cells depended on the time of immersion: 24 minutes/minute at 45 degrees C. Radiation-induced division delay occurred at a rate of 45 minutes/gray of X-irradiation. When hyperthermic exposure and X-irradiation were combined with less than 1 minute between treatments, a division delay resulted that was approximately the sum of the delays produced by the individual treatments. As the interval between treatments was increased, the overall division delay also increased beyond that which could be accounted for solely by the postponement of the second treatment. These results indicate that hyperthermia and radiation induce division delay by different mechanisms

  7. The response of normal and ataxia-telangiectasia cells to bleomycin: relationships between chromosome damage, cell cycle delay and cell killing.

    Science.gov (United States)

    Zampetti-Bosseler, F; Scott, D

    1985-08-01

    In agreement with our earlier observation (Scott and Zampetti-Bosseler, 1982) on X-irradiated normal and ataxia-telangiectasia (A-T) fibroblasts, we now report that after bleomycin or neocarzinostatin treatment also, A-T cells exhibit less G2 delay than normal cells. We confirm that A-T cells sustain more chromosome damage and lethality than normal cells after bleomycin. These observations support the hypothesis (Painter and Young, 1980) that A-T cells are defective in the recognition of certain lesions which normally lead to delays in progression through the cell cycle, during which they are repaired, and which, if unrepaired, lead to cell-lethal chromosome damage. However, we find that after bleomycin, as opposed to X-rays, the contribution of this type of lesion to cell death is minimal. The predominant lesions leading to cell death after bleomycin are not manifested at chromosome aberrations and do not lead to G2 delay or DNA-synthesis inhibition. A-T cells are defective in the recognition and/or repair of both types of lesion.

  8. Delayed Diagnosis: Giant Basal Cell Carcinoma of Scalp

    Directory of Open Access Journals (Sweden)

    Didem Didar Balcı,

    2008-07-01

    Full Text Available Although basal cell carcinoma (BCC is the most common form of skin cancer, the scalp lesions of BCC have been rarely reported. Giant BCC is defined as a tumor larger than 5 cm in diameter and only 0.5-1 % of all BCCs achieve this size. We report a case of giant BCC on the scalp that was treated with topical coticosteroids and antifungal shampoo for five years. BCC should be considered in the differential diagnosis in erythematous plaque type lesions resistant to therapy with long duration localized on the scalp.

  9. A low-power DCO using inverter interlaced cascaded delay cell

    Institute of Scientific and Technical Information of China (English)

    Huang Qiang; Fan Tao; Dai Xiangming; Yuan Guoshun

    2014-01-01

    This paper presents a low-power small-area digitally controlled oscillator (DCO) using an inverters interlaced cascaded delay cell (ⅡCDC).It uses a coarse-fine architecture with binary-weighted delay stages for the delay range and resolution.The coarse-tuning stage of the DCO uses ⅡCDC,which is power and area efficient with low phase noise,as compared with conventional delay cells.The ADPLL with a DCO is fabricated in the UMC 180-nm CMOS process with an active area of 0.071 mm2.The output frequency range is 140-600 MHz at the power supply of 1.8 V.The power consumption is 2.34 mW@a 200 MHz output.

  10. Induction of delayed-type hypersensitivity by the T cell line specific to bacterial peptidoglycans

    International Nuclear Information System (INIS)

    A T cell line specific for the chemically well-defined peptidoglycan of bacterial cell wall, disaccharide tetrapeptide, was established from Lewis rats immunized with the antigen covalently linked to the autologous rat serum albumin. The antigen specificity was examined with various analogues or derivatives of the peptidoglycan. The cell line was reactive to analogues with the COOH-terminal D-amino acid, but least reactive to those with L-amino acid as COOH terminus. Transferring of the T cell line into X-irradiated normal Lewis rats induced delayed-type hypersensitivity in an antigen specific manner

  11. Diagnostic delay in oral squamous cell carcinoma: the role of cognitive and psychological variables

    OpenAIRE

    Panzarella, Vera; Pizzo, Giuseppe; Calvino, Francesco; Compilato, Domenico; Colella, Giuseppe; Campisi, Giuseppina

    2013-01-01

    This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age: 62 years, M/F: 2.39∶1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included: sociodemographic, health-related...

  12. THE DIRECT INFLUENCE OF THE CELL PERIMETER ON THE HANDOVER DELAY IN THE BROADBAND NETWORK

    Directory of Open Access Journals (Sweden)

    Elmabruk S M Elgembari

    2014-03-01

    Full Text Available One of the main keys of positioning and ranging technologies in wireless telecommunication networks is the values of distance and RSSI (Received Signal Strength Indication, side along with the cell perimeter have a significant relationship for the effect of the network quality in terms of quality in services and connectivity, and not less in the roaming stage. Many research results drove to influence these keys to the handover delay in the broadband network, so in many cases that MT handover between the boarders of location areas or zones has been affected by long time delay and packet data lost. Over recent years many signal propagation schemes have been presented to describe the relationship between cell size and Mobile terminal distance between the current and the targeted base station and RSSI. In this paper, the modify scheme of the location management area (LMA -based multimedia broadcast services scheme has been presented , the effect of cell size and distance between BS and MT and the RSSI , which shown their influence of the handoff delay . The analytical algorithm results showed the reduction of the handover delay in smaller perimeter cell size compared to the large cells in location management area.

  13. Anatomic Invasive Depth Predicts Delayed Cervical Lymph Node Metastasis of Tongue Squamous Cell Carcinoma.

    Science.gov (United States)

    Mitani, Sohei; Tomioka, Toshifumi; Hayashi, Ryuichi; Ugumori, Toru; Hato, Naohito; Fujii, Satoshi

    2016-07-01

    Delayed cervical lymph node metastasis (CLNM) is the most negative prognostic factor of tongue squamous cell carcinoma (SCC). This study analyzed the relationship between clinicopathologic factors, including anatomic invasive depth (AID), and CLNM. A total of 212 patients with clinically node-negative (cN0) tongue SCC who had undergone partial glossectomy through the mouth were eligible for this retrospective study. The deepest portions where tongue SCC cells invaded as determined by microscopic analyses were classified into 5 categories, including epithelial and submucosal tissue, lateral extrinsic tongue muscle (ETM), intrinsic tongue muscles (ITM), paralingual and sublingual spaces, and medial ETM according to AID. We examined the relationship between clinicopathologic factors including AID and delayed CLNM. Multivariate analysis demonstrated that AID was an independent predictive factor for delayed CLNM (P=0.0022; odds ratio=7.1). Deeper invasion than ITM, including ITM, paralingual and sublingual spaces, and medial ETM, had high sensitivity and negative predictive value for delayed CLNM (94.4% and 95.7%, respectively). Precise elucidation of AID may be useful for the preoperative decision for performing elective neck dissection. None of 11 patients in whom the deepest portion where tumor invaded to lateral ETM (according to AID) showed delayed CLNM, although tongue SCC T4a tumor is defined by the presence of invasion of cancer cells to ETM. Tumors with invasion to lateral ETM might have to be excluded from the pathologic T4a category. PMID:27186852

  14. Improving Accuracy in Arrhenius Models of Cell Death: Adding a Temperature-Dependent Time Delay.

    Science.gov (United States)

    Pearce, John A

    2015-12-01

    The Arrhenius formulation for single-step irreversible unimolecular reactions has been used for many decades to describe the thermal damage and cell death processes. Arrhenius predictions are acceptably accurate for structural proteins, for some cell death assays, and for cell death at higher temperatures in most cell lines, above about 55 °C. However, in many cases--and particularly at hyperthermic temperatures, between about 43 and 55 °C--the particular intrinsic cell death or damage process under study exhibits a significant "shoulder" region that constant-rate Arrhenius models are unable to represent with acceptable accuracy. The primary limitation is that Arrhenius calculations always overestimate the cell death fraction, which leads to severely overoptimistic predictions of heating effectiveness in tumor treatment. Several more sophisticated mathematical model approaches have been suggested and show much-improved performance. But simpler models that have adequate accuracy would provide useful and practical alternatives to intricate biochemical analyses. Typical transient intrinsic cell death processes at hyperthermic temperatures consist of a slowly developing shoulder region followed by an essentially constant-rate region. The shoulder regions have been demonstrated to arise chiefly from complex functional protein signaling cascades that generate delays in the onset of the constant-rate region, but may involve heat shock protein activity as well. This paper shows that acceptably accurate and much-improved predictions in the simpler Arrhenius models can be obtained by adding a temperature-dependent time delay. Kinetic coefficients and the appropriate time delay are obtained from the constant-rate regions of the measured survival curves. The resulting predictions are seen to provide acceptably accurate results while not overestimating cell death. The method can be relatively easily incorporated into numerical models. Additionally, evidence is presented

  15. Diagnostic delay in oral squamous cell carcinoma:the role of cognitive and psychological variables

    Institute of Scientific and Technical Information of China (English)

    Vera Panzarella; Giuseppe Pizzo; Francesco Calvino; Domenico Compilato; Giuseppe Colella; Giuseppina Campisi

    2014-01-01

    This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age:62 years, M/F:2.39:1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included:sociodemographic, health-related, cognitive and psychological variables. The analysis was conducted by considering two different delay ranges:dichotomous (f1 month vs. .1 month) and polytomous (,1 month, 1-3 months, .3 months) delay. Data were investigated by univariate and multivariate analyses and a P value f0.05 was considered statistically significant. For both delay measurements, the most relevant variables were:‘Personal experience of cancer’ (dichotomous delay:P50.05, odds ratio (OR)50.33, 95%confidence interval (CI)50.11-0.99;polytomous delay:P50.006, Chi-square510.224) and‘Unawareness’ (dichotomous delay:P,0.01, OR54.96, 95%CI52.16-11.37;polytomous delay:P50.087, Chi-square54.77). Also‘Denial’ (P,0.01, OR56.84, 95%CI52.31-20.24) and‘Knowledge of cancer’ (P50.079, Chi-square58.359) were found to be statistically significant both for dichotomous and for polytomous categorization of delay, respectively. The findings of this study indicated that, in the investigated cohorts, the knowledge about cancer issues is strongly linked to the patient delay. Educational interventions on the Mediterranean population are necessary in order to increase the patient awareness and to emphasize his/her key role in early diagnosis of OSCC.

  16. Decrease in spermidine content during logarithmic phase of cell growth delays spore formation of Bacillus subtilis.

    Science.gov (United States)

    Ishii, I; Takada, H; Terao, K; Kakegawa, T; Igarashi, K; Hirose, S

    1994-11-01

    Bacillus subtilis 168M contained a large amount of spermidine during the logarithmic phase of growth, but the amount decreased drastically during the stationary phase. The extracts, prepared from B. subtilis cells harvested in the logarithmic phase, contained activity of arginine decarboxylase (ADC) rather than the activity of ornithine decarboxylase. In the presence of alpha-difluoromethylarginine (DFMA), a specific and irreversible inhibitor of ADC, the amount of spermidine in B. subtilis during the logarithmic phase decreased to about 25% of the control cells. Under these conditions, spore formation of B. subtilis 168M delayed greatly without significant inhibition of cell growth. The decrease in spermidine content in the logarithmic phase rather than in the stationary phase was involved in the delay of sporulation. Electron microscopy of cells at 24 hrs. of culture confirmed the delay of spore formation by the decrease of spermidine content. Furthermore, the delay of sporulation was negated by the addition of spermidine. These data suggest that a large amount of spermidine existing during the logarithmic phase plays an important role in the sporulation of B. subtilis.

  17. Transplanted adipose-derived stem cells delay D-galactose-induced aging in rats

    Institute of Scientific and Technical Information of China (English)

    Chun Yang; Ou Sha; Jingxing Dai; Lin Yuan; Dongfei Li; Zhongqiu Wen; Huiying Yang; Meichun Yu; Hui Tao; Rongmei Qu; Yikuan Du; Yong Huang

    2011-01-01

    To investigate the effects of allogeneically transplanted, adipose-derived stem cells in aging rats, in the present study, we established a rat model of subacute aging using continuous subcutaneous injections of D-galactose. Two weeks after the adipose-derived stem cells transplantations, serum superoxide dismutase activity was significantly increased, malondialdehyde content was significantly reduced, hippocampal neuronal degeneration was ameliorated, the apoptotic index of hippocampal neurons was decreased, and learning and memory function was significantly improved in the aging rats. These results indicate that allogeneic transplantation of adipose-derived stem cells may effectively delay D-galactose-induced aging.

  18. CALCULUS FROM THE PAST: MULTIPLE DELAY SYSTEMS ARISING IN CANCER CELL MODELLING

    KAUST Repository

    WAKE, G. C.

    2013-01-01

    Nonlocal calculus is often overlooked in the mathematics curriculum. In this paper we present an interesting new class of nonlocal problems that arise from modelling the growth and division of cells, especially cancer cells, as they progress through the cell cycle. The cellular biomass is assumed to be unstructured in size or position, and its evolution governed by a time-dependent system of ordinary differential equations with multiple time delays. The system is linear and taken to be autonomous. As a result, it is possible to reduce its solution to that of a nonlinear matrix eigenvalue problem. This method is illustrated by considering case studies, including a model of the cell cycle developed recently by Simms, Bean and Koeber. The paper concludes by explaining how asymptotic expressions for the distribution of cells across the compartments can be determined and used to assess the impact of different chemotherapeutic agents. Copyright © 2013 Australian Mathematical Society.

  19. DNA damage enhanced by the attenuation of SLD5 delays cell cycle restoration in normal cells but not in cancer cells.

    Directory of Open Access Journals (Sweden)

    Zhi-Yuan Gong

    Full Text Available SLD5 is a member of the GINS complex composed of PSF1, PSF2, PSF3 and SLD5, playing a critical role in the formation of the DNA replication fork with CDC45 in yeast. Previously, we had isolated a PSF1 orthologue from a murine hematopoietic stem cell DNA library and were then able to identify orthologues of all the other GINS members by the yeast two hybrid approach using PSF1 as the bait. These GINS orthologues may also function in DNA replication in mammalian cells because they form tetrameric complexes as observed in yeast, and gene deletion mutants of both PSF1 and SLD5 result in a lack of epiblast proliferation and early embryonic lethality. However, we found that PSF1 is also involved in chromosomal segregation in M phase, consistent with recent suggestions that homologues of genes associated with DNA replication in lower organisms also regulate cellular events other than DNA replication in mammalian cells. Here we analyzed the function of SLD5 other than DNA replication and found that it is active in DNA damage and repair. Attenuation of SLD5 expression results in marked DNA damage in both normal cells and cancer cells, suggesting that it protects against DNA damage. Attenuation of SLD5 delays the DNA repair response and cell cycle restoration in normal cells but not in cancer cells. These findings suggest that SLD5 might represent a therapeutic target molecule acting at the level of tumor stromal cells rather than the cancerous cells themselves, because development of the tumor microenvironment could be delayed or disrupted by the suppression of its expression in the normal cell types within the tumor.

  20. Carbofuran alters centrosome and spindle organization, and delays cell division in oocytes and mitotic cells.

    Science.gov (United States)

    Cinar, Ozgur; Semiz, Olcay; Can, Alp

    2015-04-01

    Although many countries banned of its usage, carbofuran (CF) is still one of the most commonly used carbamate derivative insecticides against insects and nematodes in agriculture and household, threatening the human and animal health by contaminating air, water, and food. Our goal was to evaluate the potential toxic effects of CF on mammalian oocytes besides mitotic cells. Caspase-dependent apoptotic pathway was assessed by immunofluorescence and western blot techniques. Alterations in the meiotic spindle formation after CF exposure throughout the in vitro maturation of mice oocyte-cumulus complexes (COCs) were analyzed by using a 3D confocal laser microscope. Maturation efficiency and kinetics were assessed by direct observation of the COCs. Results indicated that the number of TUNEL-positive cells increased in CF-exposed groups, particularly higher doses (>250 µM) in a dose-dependent fashion. The ratio of anticleaved caspase-3 labeled cells in those groups positively correlated with TUNEL-positivity. Western blot analysis confirmed a significant increase in active caspase-3 activity. CF caused a dose-dependent accumulation of oocytes at prometaphase-I (PM-I) of meiosis. Partial loss of spindle microtubules (MTs) was noted, which consequently gave rise to a diamond shape spindle. Aberrant pericentrin foci were noted particularly in PM-I and metaphase-I (M-I) stages. Conclusively, CF (1) induces programmed cell death in a dose-dependent manner, and (2) alters spindle morphology most likely through a mechanism that interacts with MT assembly and/or disorientation of pericentriolar proteins. Overall, data suggest that CF could give rise to aneuploidy or cell death in higher doses, therefore reduce fertilization and implantation rates.

  1. Reduced cell cohesiveness of outgrowths from eccrine sweat glands delays wound closure in elderly skin.

    Science.gov (United States)

    Rittié, Laure; Farr, Elyssa A; Orringer, Jeffrey S; Voorhees, John J; Fisher, Gary J

    2016-10-01

    Human skin heals more slowly in aged vs. young adults, but the mechanism for this delay is unclear. In humans, eccrine sweat glands (ESGs) and hair follicles underlying wounds generate cohesive keratinocyte outgrowths that expand to form the new epidermis. Here, we compared the re-epithelialization of partial-thickness wounds created on the forearm of healthy young ( 70 yo) adults. Our results confirm that the outgrowth of cells from ESGs is a major feature of repair in young skin. Strikingly, in aged skin, although ESG density is unaltered, less than 50% of the ESGs generate epithelial outgrowths during repair (vs. 100% in young). Surprisingly, aging does not alter the wound-induced proliferation response in hair follicles or ESGs. Instead, there is an overall reduced cohesiveness of keratinocytes in aged skin. Reduced cell-cell cohesiveness was most obvious in ESG-derived outgrowths that, when present, were surrounded by unconnected cells in the scab overlaying aged wounds. Reduced cell-cell contact persisted during the repair process, with increased intercellular spacing and reduced number of desmosomes. Together, reduced outgrowths of ESG (i) reduce the initial number of cells participating in epidermal repair, (ii) delay wound closure, and (iii) lead to a thinner repaired epidermis in aged vs. young skin. Failure to form cohesive ESG outgrowths may reflect impaired interactions of keratinocytes with the damaged ECM in aged skin. Our findings provide a framework to better understand the mediators of delayed re-epithelialization in aging and further support the importance of ESGs for the repair of human wounds. PMID:27184009

  2. Delay of ZGA initiation occurred in 2-cell blocked mouse embryos

    Institute of Scientific and Technical Information of China (English)

    JIA JING QIU; WU WEN ZHANG; ZHI LI WU; YI HONG WANG; MIN QIAN; YI PING LI

    2003-01-01

    One-cell mouse embryos from KM strain and B6C3F1 strain were cultured in M16 medium, in which2-cell block generally occurs. Embryos of KM strain exhibited 2-cell block, whereas B6C3F1 embryos,which are regarded as a nonblocking strain, proceeded to the 4-cell stage in our culture condition. It is oftenassumed that the block of early development is due to the failure of zygotic gene activation (ZGA) in culturedembryos. In this study we examined protein synthesis patterns by two-dimensional gel electrophoresis of[35S] methionine radiolabeled 2-cell embryos. Embryos from the blocking strain and the nonblocking strainwere compared in their development both in vitro and in vivo. The detection of TRC expression, a markerof ZGA, at 42 h post hCG in KM embryos developed in vitro suggested that ZGA was also initiated even inthe 2-cell arrested embryos. Nevertheless, a significant delay of ZGA was observed in KM strain as comparedwith normally developed B6C3F1 embryos. At the very beginning of major ZGA as early as 36 h post hCG,TRC has already been expressed in B6C3F1 embryos developed in vitro and KM embryos developed in vivo.But for 2-cell blocked KM embryos, TRC was still not detectable even at 38 h post hCG. These evidencessuggest that 2-cell-blocked embryos do initiate ZGA, and that 2-cell block phenomenon is due not to thedisability in initiating ZGA, but to a delay of ZGA.

  3. Recurrent gastrointestinal bleeding diagnosed by delayed scintigraphy with Tc-99m-labeled red blood cells.

    Science.gov (United States)

    Nwakanma, Lois; Meyerrose, Gary; Kennedy, Shalyn; Rakvit, Ariwan; Bohannon, Todd; Silva, Micheal

    2003-08-01

    A 56-year-old woman presented with bright-red blood from the rectum. Esophagogastroduodenoscopy revealed mild gastritis. Colonoscopy demonstrated diverticulosis without active bleeding, and in vitro tagged red blood cell scintigraphy was unremarkable. There was no further evidence of bleeding and the patient was discharged home. The patient returned with recurrent bright-red blood from the rectum. Although delayed scintigraphic images seldom demonstrate the site of bleeding, delayed images at 12 hours demonstrated active bleeding near the hepatic flexure in this patient. This was confirmed with selective mesenteric angiography, and was treated with coil embolization of the tertiary branches of the right middle colic artery. PMID:12897664

  4. Diminished Memory T-Cell Expansion Due to Delayed Kinetics of Antigen Expression by Lentivectors.

    Directory of Open Access Journals (Sweden)

    Karina Furmanov

    Full Text Available Memory CD8(+ T lymphocytes play a central role in protective immunity. In attempt to increase the frequencies of memory CD8(+ T cells, repeated immunizations with viral vectors are regularly explored. Lentivectors have emerged as a powerful vaccine modality with relatively low pre-existing and anti-vector immunity, thus, thought to be ideal for boosting memory T cells. Nevertheless, we found that lentivectors elicited diminished secondary T-cell responses that did not exceed those obtained by priming. This was not due to the presence of anti-vector immunity, as limited secondary responses were also observed following heterologous prime-boost immunizations. By dissecting the mechanisms involved in this process, we demonstrate that lentivectors trigger exceptionally slow kinetics of antigen expression, while optimal activation of lentivector-induced T cells relays on durable expression of the antigen. These qualities hamper secondary responses, since lentivector-encoded antigen is rapidly cleared by primary cytotoxic T cells that limit its presentation by dendritic cells. Indeed, blocking antigen clearance by cytotoxic T cells via FTY720 treatment, fully restored antigen presentation. Taken together, while low antigen expression is expected during secondary immunization with any vaccine vector, our results reveal that the intrinsic delayed expression kinetics of lentiviral-encoded antigen, further dampens secondary CD8(+ T-cell expansion.

  5. The influence of fixation delay on mitotic activity and flow cytometric cell cycle variables.

    Science.gov (United States)

    Bergers, E; Jannink, I; van Diest, P I; Cuesta, M A; Meyer, S; van Mourik, J C; Baak, J P

    1997-01-01

    Proliferation variables such as mitotic activity and the percentage of S-phase cells have been shown to be of prognostic value in many tumors, especially in breast cancer. However, some studies reported a decrease in mitotic activity caused by delay in fixation of the tissue. In contrast, other studies showed that the identifiability of mitotic figures decreases after fixation delay, but the total number of mitotic figures and also the percentage of S-phase cells remain unchanged. Most studies have been done on small numbers of experimental tumors, thus introducing the risk of selection bias. The aim of this study was to reinvestigate the influence of fixation delay on mitotic activity and cell cycle variables assessed by flow cytometry in an adequate number of resected human tissues to reach firmer conclusions. Resection specimens of 19 and 21 cases, respectively, for the mitotic activity estimate and the flow cytometric percentage of S-phase calculation were collected directly from the operating theater using lung, breast, and intestinal cancers and normal intestinal mucosa. The tissues were cut in pieces, and from each specimen, pieces were fixed in 4% buffered formaldehyde (for mitosis counting) as well as snap frozen (for flow cytometry) immediately after excision, as well as after a fixation delay of 1, 2, 4, 6, 8, 18, and 24 hours. Moreover, during the fixation delay, one series from each specimen was kept in the refrigerator and the second at room temperature. Thus, a total of 304 (19 X 16) and 336 (21 X 16) specimens were investigated for the mitotic activity estimate and the percentage of S-phase cells calculation, respectively. With regard to the estimation of the mitotic activity, both clear and doubtful mitotic figures were registered separately, obtaining an "uncorrected" and "corrected" (for doubtful mitotic figures) mitotic activity estimate. The percentage of S-phase cells was obtained by cell cycle analysis of flow cytometric DNA-histograms. The

  6. Enhancing endogenous stem cells in the newbornvia delayed umbilical cord clamping

    Institute of Scientific and Technical Information of China (English)

    Christopher Lawton; Sandra Acosta; Nate Watson; Chiara Gonzales-Portillo; hTeo Diamandis; Naoki Tajiri; Yuji Kaneko; Paul R. Sanberg; Cesar V. Borlongan

    2015-01-01

    There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal beneifts including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deifciency anemia in term infants. Human umbilical cord blood con-tains signiifcant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it en-hances blood lfow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant’s susceptibility to both neonatal and age-related diseases.

  7. Delayed cord clamping in red blood cell alloimmunization: safe, effective, and free?

    Science.gov (United States)

    McAdams, Ryan M

    2016-04-01

    Hemolytic disease of the newborn (HDN), an alloimmune disorder due to maternal and fetal blood type incompatibility, is associated with fetal and neonatal complications related to red blood cell (RBC) hemolysis. After delivery, without placental clearance, neonatal hyperbilirubinemia may develop from ongoing maternal antibody-mediated RBC hemolysis. In cases refractory to intensive phototherapy treatment, exchange transfusions (ET) may be performed to prevent central nervous system damage by reducing circulating bilirubin levels and to replace antibody-coated red blood cells with antigen-negative RBCs. The risks and costs of treating HDN are significant, but appear to be decreased by delayed umbilical cord clamping at birth, a strategy that promotes placental transfusion to the newborn. Compared to immediate cord clamping (ICC), safe and beneficial short-term outcomes have been demonstrated in preterm and term neonates receiving delayed cord clamping (DCC), a practice that may potentially be effective in cases RBC alloimmunization. PMID:27186530

  8. A digital TDC with a reduced number of delay line cells

    CERN Document Server

    Boujrad, A; Tripon, M

    2002-01-01

    In nuclear physics experiments, a decision maker named as 'trigger' gives a bit pattern which allows the fired detectors identification. As the data acquisition dead time is greater than the time between physical events, timing information is essential. We add to the trigger function a Time to Digital Converter (TDC) in order to make a separation between events. The paper describes the architecture chosen for the TDC and illustrates the contribution of each element to the TDC performance. An eight-bit counter is used for the dynamic range of the TDC (in microsecond) associated to a delay line improving the resolution (in nanosecond). The study shows that exploiting the two system clock states (high and low) allows to reduce the number of delay line cells. The Differential Nonlinearity Measurements are given for different resolutions (1, 2 and 5 ns) and illustrate the clock period, the clock duty cycle and the delay line contributions to the TDC performances.

  9. Evaluation of 14 cases of oral squamous cell carcinoma with delayed diagnosis

    Directory of Open Access Journals (Sweden)

    Renata TUCCI

    2010-06-01

    Full Text Available Introduction: Pathological processes of several causes such as infectious,inflammatory, immunological, allergic, systemic and traumatic diseases often affect the oral cavity. The dentist is responsible for the diagnosis of these oral lesions. Likewise, the dentist is responsible for the oral cancer diagnosis. The oral cavity allows direct visualization of the structures,which facilitates the identification of initial lesions and, consequently, there should be a higher probability of early diagnosis of oral lesions.However, there are still many cases of oral cancer in Brazil with delayed diagnosis, which implies a worse prognosis and a decrease in the survival rate of patients. Objective, case report and conclusion: The aim of this work is to report oral squamous cell carcinoma cases with delayed diagnosis in the Stomatology Department of the Cuiabá Cancer Hospital (MT, Brazil, as well as to discuss the main reasons that lead to the delay in diagnosis, besides giving suggestions to modify this situation.

  10. Reduction of ARNT in myeloid cells causes immune suppression and delayed wound healing

    OpenAIRE

    Scott, Christopher; Bonner, James; Min, Danqing; Boughton, Philip; Stokes, Rebecca; Cha, Kuan Minn; Walters, Stacey N.; Maslowski, Kendle; Sierro, Frederic; Grey, Shane T.; Twigg, Stephen; McLennan, Susan; Gunton, Jenny E.

    2014-01-01

    Aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor that binds to partners to mediate responses to environmental signals. To investigate its role in the innate immune system, floxed ARNT mice were bred with lysozyme M-Cre recombinase animals to generate lysozyme M-ARNT (LAR) mice with reduced ARNT expression. Myeloid cells of LAR mice had altered mRNA expression and delayed wound healing. Interestingly, when the animals were rendered diabetic, the difference in wou...

  11. Cell survival and growth delay in rat R-1 tumours after radiation and vinblastine treatment

    International Nuclear Information System (INIS)

    The rat R-1 rhabdomyosarcoma with a capacity for colony growth in vitro after excision of the tumour and dissociation by a trypsin method was used to investigate the effectiveness of radio-chemotherapy. Growth delay data were compared with data on survival of cells derived from tumours treated in situ. An excess in growth delay was observed when vinblastine (1.5 mg/kg) was given at intervals of 0.3 to 2 d after or 4 d before a dose of 20 Gy of X-rays. Cell survival data indicated that the maximum effectiveness of the drug treatment and the combined treatment (vinblastine and a dose of 10 Gy) can be assessed 2 to 3 d after treatment. The fractions of surviving cells determined after combined therapy at 0,1 and 2 d intervals were not significantly different from the fractions expected on the basis of simple multiplication of the fractions surviving individual treatments. The data suggested that the excess in tumour growth delay observed cannot be accounted for by co-operative interaction of the doses of radiation and drug. (author)

  12. Time delay control for fuel cells with bidirectional DC/DC converter and battery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.B. [Mechanical Engineering Department, Chonnam National University, Gwangju (Korea); Kang, S.J. [Mechatronics Engineering Department, Korea Polytechnic College V, Gwangju (Korea)

    2010-08-15

    Transient behavior is a key property in the vehicular application of proton exchange membrane (PEM) fuel cells. A better control technology is constructed to increase the transient performance of PEM fuel cells. A steady-state isothermal analytical fuel cell model is constructed to analyze mass transfer and water transport in the membrane. To prevent the starvation of air in the PEM fuel cell, time delay control is used to regulate the optimum stoichiometric amount of oxygen, although dynamic fluctuations exist in the PEM fuel cell power. A bidirectional DC/DC converter connects the battery to the DC link to manage the power distribution between the fuel cell and the battery. Dynamic evolution control (DEC) allows for adequate pulse-width modulation (PWM) control of the bidirectional DC/DC converter with fast response. Matlab/Simulink/Simpower simulation is performed to validate the proposed methodology, increase the transient performance of the PEM fuel cell system and satisfy the requirement of energy management. (author)

  13. Improving dynamic performance of proton-exchange membrane fuel cell system using time delay control

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Bae [Mechanical Engineering Department, Chonnam National University, Gwangju (Korea)

    2010-10-01

    Transient behaviour is a key parameter for the vehicular application of proton-exchange membrane (PEM) fuel cell. The goal of this presentation is to construct better control technology to increase the dynamic performance of a PEM fuel cell. The PEM fuel cell model comprises a compressor, an injection pump, a humidifier, a cooler, inlet and outlet manifolds, and a membrane-electrode assembly. The model includes the dynamic states of current, voltage, relative humidity, stoichiometry of air and hydrogen, cathode and anode pressures, cathode and anode mass flow rates, and power. Anode recirculation is also included with the injection pump, as well as anode purging, for preventing anode flooding. A steady-state, isothermal analytical fuel cell model is constructed to analyze the mass transfer and water transportation in the membrane. In order to prevent the starvation of air and flooding in a PEM fuel cell, time delay control is suggested to regulate the optimum stoichiometry of oxygen and hydrogen, even when there are dynamical fluctuations of the required PEM fuel cell power. To prove the dynamical performance improvement of the present method, feed-forward control and Linear Quadratic Gaussian (LQG) control with a state estimator are compared. Matlab/Simulink simulation is performed to validate the proposed methodology to increase the dynamic performance of a PEM fuel cell system. (author)

  14. Comparison of the protective action of glutathione and cysteamine on radiation-induced mitotic delay in cultured S-5 cells.

    Science.gov (United States)

    Kawasaki, S; Kobayashi, M; Hashimoto, H; Nakanishi, T

    1979-06-01

    The protective effect of glutathione (GSH) and cysteamine (MEA) on radiation-induced mitotic delay in cultured mammalian L-5 cells was studied. Cells treated with 20 mM of GSH during irradiation with 2 Gy (200 rad) showed faster recovery of the mitotic index than control cells irradiated without chemical treatment; however, GSH had no effect on mitotic delay time. Inhibition of mitosis was observed with 80, 100, and 120 mM of GSH. Cells treated with 5 mM of MEA during irradiation also showed faster recovery of the mitotic index than the controls, but in addition the delay time was shortened. Progression of G2-phase cells treated with 5-fluorouracil to mitosis after irradiation was protected by MEA but not by GSH. Progression of S-phase cells labeled with 3H-thymidine to mitosis was accelerated by both agents during irradiation.

  15. A delay prior to mitotic entry triggers caspase 8-dependent cell death in p53-deficient Hela and HCT-116 cells.

    Science.gov (United States)

    Silva, Victoria C; Plooster, Melissa; Leung, Jessica C; Cassimeris, Lynne

    2015-01-01

    Stathmin/Oncoprotein 18, a microtubule destabilizing protein, is required for survival of p53-deficient cells. Stathmin-depleted cells are slower to enter mitosis, but whether delayed mitotic entry triggers cell death or whether stathmin has a separate pro-survival function was unknown. To test these possibilities, we abrogated the cell cycle delay by inhibiting Wee1 in synchronized, stathmin-depleted cells and found that apoptosis was reduced to control levels. Synchronized cells treated with a 4 hour pulse of inhibitors to CDK1 or both Aurora A and PLK1 delayed mitotic entry and apoptosis was triggered only in p53-deficient cells. We did not detect mitotic defects downstream of the delayed mitotic entry, indicating that cell death is activated by a mechanism distinct from those activated by prolonged mitotic arrest. Cell death is triggered by initiator caspase 8, based on its cleavage to the active form and by rescue of viability after caspase 8 depletion or treatment with a caspase 8 inhibitor. In contrast, initiator caspase 9, activated by prolonged mitotic arrest, is not activated and is not required for apoptosis under our experimental conditions. P53 upregulates expression of cFLIPL, a protein that blocks caspase 8 activation. cFLIPL levels are lower in cells lacking p53 and these levels are reduced to a greater extent after stathmin depletion. Expression of FLAG-tagged cFLIPL in p53-deficient cells rescues them from apoptosis triggered by stathmin depletion or CDK1 inhibition during G2. These data indicate that a cell cycle delay in G2 activates caspase 8 to initiate apoptosis specifically in p53-deficient cells.

  16. Targeting CD45RB alters T cell migration and delays viral clearance.

    Science.gov (United States)

    Lim, Bock; Sutherland, Robyn M; Zhan, Yifan; Deliyannis, Georgia; Brown, Lorena E; Lew, Andrew M

    2006-02-01

    CD45 is a receptor tyrosine phosphatase essential for TCR signaling. One isoform, CD45RB, is down-regulated in memory cells and targeting CD45RB with a specific antibody has been shown to inhibit graft rejection. Its role in immunity to infection, however, has not been tested. Here, we report the effect of anti-CD45RB antibody treatment on the induction of anti-influenza CD8+ T cells and viral clearance. Anti-CD45RB-treated mice had delayed pulmonary viral clearance compared with untreated mice whose infection was completely cleared by day 8 post-infection. In anti-CD45RB-treated mice, the total CD4+ and CD8+ T cell numbers in both the lungs and mediastinal nodes were substantially reduced at days 5 and 8; this effect was less marked for the spleen. CD8+ T cells specific for influenza virus were also reduced compared with the control group in all three organs at day 8. By day 11, when both treated and control groups showed no virus remaining in the lungs, specific CD8+ T cell numbers were at similar low levels. Homing to lymph nodes and lung of dye-labeled T cells was greatly inhibited (by >80%) by anti-CD45RB treatment. This reduced homing corresponded with reduced CD62L and beta1-integrin expression in both uninfected and infected mice. Since CD62L plays a critical role in homing lymphocytes to lymph nodes, and high levels of CD62L and alpha4beta1-integrin are expressed by lymphocytes that home to bronchus-associated lymphoid tissue, we suggest that reduced expression of these molecules is a key explanation for the delay in immune responses. PMID:16361310

  17. Haem oxygenase delays programmed cell death in wheat aleurone layers by modulation of hydrogen peroxide metabolism.

    Science.gov (United States)

    Wu, Mingzhu; Huang, Jingjing; Xu, Sheng; Ling, Tengfang; Xie, Yanjie; Shen, Wenbiao

    2011-01-01

    Haem oxygenase-1 (HO-1) confers protection against a variety of oxidant-induced cell and tissue injury in animals and plants. In this report, it is confirmed that programmed cell death (PCD) in wheat aleurone layers is stimulated by GA and prevented by ABA. Meanwhile, HO activity and HO-1 protein expression exhibited lower levels in GA-treated layers, whereas the hydrogen peroxide (H(2)O(2)) content was apparently increased. The pharmacology approach illustrated that scavenging or accumulating H(2)O(2) either delayed or accelerated GA-induced PCD. Furthermore, pretreatment with the HO-1 specific inhibitor, zinc protoporphyrin IX (ZnPPIX), before exposure to GA, not only decreased HO activity but also accelerated GA-induced PCD significantly. The application of the HO-1 inducer, haematin, and the enzymatic reaction product of HO, carbon monoxide (CO) aqueous solution, both of which brought about a noticeable induction of HO expression, substantially prevented GA-induced PCD. These effects were reversed when ZnPPIX was added, suggesting that HO in vivo played a role in delaying PCD. Meanwhile, catalase (CAT) and ascorbate peroxidase (APX) activities or transcripts were enhanced by haematin, CO, or bilirubin (BR), the catalytic by-product of HO. This enhancement resulted in a decrease in H(2)O(2) production and a delay in PCD. In addition, the antioxidants butylated hydroxytoluene (BHT), dithiothreitol (DTT), and ascorbic acid (AsA) were able not only to delay PCD but also to mimic the effects of haematin and CO on HO up-regulation. Overall, the above results suggested that up-regulation of HO expression delays PCD through the down-regulation of H(2)O(2) production.

  18. Regulation of delayed-type hypersensitivity: VI. Antigen-specific suppressor T cells and suppressor factor for delayed-type hypersensitivity to histocompatibility antigens

    International Nuclear Information System (INIS)

    Mice develop highly significant levels of delayed-type hypersensitivity (DTH) to major and minor histocompatibility antigens when injected s.c. with lymphoid cells from X-irradiated allogeneic donors. However, when mice are inoculated i.v. with a high dose of X-irradiated allogeneic lymphoid cells, they not only fail to develop DTH to the allogeneic cells, but their ability to respond to an immunogenic challenge of the alloantigens is also significantly depressed. This suppression is adoptively transferable by antigen-specific suppressor T cells and not by immune serum. Cell surface phenotypic analysis shows that the primary suppressor cells for alloantigens are Thy-1+, Lyt-1+2-, and Ia-, whereas the secondary suppressor cells appearing after boosting injection are Thy-+, Lyt-1+2+, and Ia-. These suppressor T (Ts) cells localize in the lymphoid organs shortly after their induction and are largely absent from the spleen or lymph node 1 month later.However, ''suppressor memory'' can be recalled by an immunogenic dose of alloantigens which would normally induce DTH effector cells rather than suppressor cells in naive mice. When the suppressor cells were cultured in vitro for 48 hr, the supernatant contained suppressive activity. It appears likely that the manifestation of the suppressor cells is via soluble, antigen-specific suppressor factor(s), the production of which is dependent on viable T cells

  19. Early and delayed reproductive death in human cells exposed to high energy iron-ion beams

    Science.gov (United States)

    Bettega, D.; Calzolari, P.; Doneda, L.; Durante, M.; Tallone, L.

    For radiation protection of the astronauts it is important to know both the acute and the late effects of charged particles. Iron is the most abundant high charge and energy (HZE) specie in galactic cosmic radiation. (HZE) ions are considered to be the major contributors to equivalent dose in space, but the Relative Biological Effectiveness of HZE particles has large uncertainties, expecially for late effects. We have determined early and delayed reproductive death in human fibroblast cells (AG1522) exposed to iron ion beams of energies between 0.2 and 1 GeV/n. The cells were irradiated at the HIMAC accelerator in Chiba (0.2 and 0.5 GeV/n) and at the AGS accelerator at the NASA Space Radiation Laboratory in Brookhaven (1 GeV/n). For each beam the dose--effect curves were measured at least twice in the dose range between 0.5 and 2 Gy. 60 Co gamma rays were used as reference radiation. The following results were obtained: 1) the 1 GeV/n beam effectiveness for inactivation of the AG1522 cells is higher than that of any other beam. 2) the progeny of the irradiated cells show the presence of delayed damage in the form of reproductive death for all the beams with the 1 GeV/n being the most effective. 3) the relative biological effectiveness of the iron beams is higher for delayed compared to early reproductive death. A comparison with preliminary results obtained with 970 MeV/n Ti and 490 MeV/n Si ions will be also reported .

  20. Cell death, chromosome damage and mitotic delay in normal human, ataxia telangiectasia and retinoblastoma fibroblasts after x-irradiation.

    Science.gov (United States)

    Zampetti-Bosseler, F; Scott, D

    1981-05-01

    We recently showed (Scott and Zampetti-Bosseler 1980) that X-ray sensitive mouse lymphoma cells sustain more chromosome damage, mitotic delay and spindle defects than X-ray resistant cells. We proposed that (a) chromosome aberrations contribute much more to lethality than spindle defects, and (b) that DNA lesions are less effectively repaired in the sensitive cells and give rise to more G2 mitotic delay and chromosome aberrations. Our present results on human fibroblasts with reported differential sensitivity to ionizing radiation (i.e. normal donors and patients with ataxia telangiectasia and retinoblastoma) support the first hypothesis since we observed a positive correlation between chromosome aberration frequencies and cell killing and no induced spindle defects. Our second hypothesis is however not substantiated since X-ray sensitive fibroblasts from the ataxia patient suffered less mitotic delay than cells from normal donors. A common lesion for mitotic delay and chromosome aberrations can still be assumed by adopting the hypothesis of Painter and Young (1981) that the defect in ataxia cells is not in repair but in a failure of DNA damage to initiate mitotic delay. In contrast to other reports, we found the retinoblastoma cells to be of normal radiation sensitivity (cell killing and aberration).

  1. Tumour growth delay and cell survival in rat R-1 tumours after radiation and methotrexate treatment

    International Nuclear Information System (INIS)

    The rat R-1 rhabdomyosarcoma which forms colonies in vitro has been used to investigate the effectiveness of radiochemotherapy. Tumour growth delay data were compared with those on survival of cells derived from tumours treated in situ. Methotrexate (MTX) was administered i.p. in three doses of 10 mg per kg body weight at intervals of 4 h. A dose of 10 Gy of 300 kV X rays was given at different time intervals before or after the MTX treatment. The observed tumour growth delays for the combined treatment for intervals of up to 4 d were less than the sum of those following separate treatments. An excess in growth delay was observed when MTX was given 6 to 8 days after or 5 days before a dose of 10 Gy. The radiation treatment resulted in fractions of surviving cells which remained constant for up to 6 days after treatment. The effectiveness of the MTX treatment could be assessed at 3d after administration of the drug, that of the combined treatments as at least 3 days after the MTX treatment. (Auth.)

  2. Human umbilical cord blood mononuclear cell transplantation for delayed encephalopathy after carbon monoxide intoxication

    Directory of Open Access Journals (Sweden)

    Gong D

    2013-08-01

    Full Text Available Dianrong Gong,1 Haiyan Yu,1 Weihua Wang,2 Haixin Yang,1 Fabin Han1,21Department of Neurology, 2Centre for Stem Cells and Regenerative Medicine, Liaocheng People's Hospital, The Affiliated Liaocheng Hospital, Taishan Medical University, Shandong, People's Republic of ChinaAbstract: Stem cell transplantation is one of the potential treatments for neurological disorders. Since human umbilical cord stem cells have been shown to provide neuroprotection and promote neural regeneration, we have attempted to transplant the human umbilical cord blood mononuclear cells (hUCB-MNCs to treat patients with delayed encephalopathy after carbon monoxide intoxication (DEACOI. The hUCB-MNCs were isolated from fresh umbilical cord blood and were given to patients subarachnoidally. Physical examinations, mini-mental state examination scores, and computed tomography scans were used to evaluate the improvement of symptoms, signs, and pathological changes of the patient's brain before and after hUCB-MNC transplantation. A total of 12 patients with DEACOI were treated with hUCB-MNCs in this study. We found that most of the patients have shown significant improvements in movement, behavior, and cognitive function, and improved brain images in 1–4 months from the first transplantation of hUCB-MNCs. None of these patients have been observed to have any severe adverse effects. Our study suggests that the hUCB-MNC transplantation may be a safe and effective treatment for DEACOI. Further studies and clinical trials with more cases, using more systematic scoring methods, are needed to evaluate brain structural and functional improvements in patients with DEACOI after hUCB-MNC therapy.Keywords: human umbilical cord blood mononuclear cells, transplantation, delayed encephalopathy after carbon monoxide intoxication, MMSE

  3. Selected Activities of Citrus Maxima Merr. Fruits on Human Endothelial Cells: Enhancing Cell Migration and Delaying Cellular Aging

    Directory of Open Access Journals (Sweden)

    Paiwan Buachan

    2014-04-01

    Full Text Available Endothelial injury and damage as well as accumulated reactive oxygen species (ROS in aging play a significant role in the development of cardiovascular disease (CVD. Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM fruit extract on human umbilical vein endothelial cell (HUVECs migration and aging. The freeze-dried powder of fruit extract was characterized for antioxidant capacity (FRAP assay and certain natural antioxidants, including ascorbic acid, gallic acid, hesperidin, and naringin (HPLC. Short-term (48 h co-cultivation of HUVECs with CM enhanced cell migration as evaluated by a scratch wound assay and Boyden chamber assay. A long-term treatment with CM for 35 days significantly increased HUVEC proliferation capability as indicated by population doubling level (PDL. CM also delayed the onset of aging phenotype shown by senescence-associated β-galactosidase (SA-β-gal staining. Furthermore, CM was able to attenuate increased ROS levels in aged cells when determined by 2′,7′-dichlorodihydrofluorescein diacetate (DCDHF while eNOS mRNA expression was increased but the eNOS protein level was not changed. Thus, further in vivo and clinical studies are warranted to support the use of pummelo as a functional fruit for endothelial health and CVD risk reduction.

  4. Delayed-type hypersensitivity response in experimental autoimmune neuritis treated with peptide-coupled spleen cells.

    Science.gov (United States)

    Gregorian, S K; Rostami, A

    1994-04-01

    Experimental autoimmune neuritis (EAN) is a T cell-mediated autoimmune inflammatory disease of the peripheral nervous system that is characterized by demyelination and mononuclear cell infiltration. It is induced in Lewis rats by administration of myelin P2 protein or a synthetic peptide (SP-26) corresponding to amino acid residues 53-78 of bovine P2 protein. Recently, we showed that SP-26, when coupled to syngeneic spleen cells and administered intravenously, provided an effective means of inducing tolerance by inhibiting the clinical signs, decreased proliferative response of lymphoid cells to SP-26 and histological changes of EAN. However, our current data indicate that, despite tolerance induction in these Lewis rats, the antigen-specific delayed-type hypersensitivity (DTH) response to SP-26 remained intact. Furthermore, interferon (IFN)-gamma production by spleen cells of tolerized rats were unchanged as compared to EAN rats. The in vitro proliferation of T lymphocytes from tolerized rats stimulated by SP-26 was reduced as compared to EAN controls but was enhanced upon addition of exogenous interleukin-2. Thus, reduction in EAN clinical signs does not necessarily indicate a decrease in DTH response and IFN-gamma production in EAN Lewis rats. The implication of this finding in regard to immunoregulatory mechanism of DTH response is discussed. PMID:7512578

  5. A NOVEL DESIGN OF MULTIPLEXER BASED FULL-ADDER CELL FOR POWER AND PROPAGATION DELAY OPTIMIZATIONS

    Directory of Open Access Journals (Sweden)

    G. RAMANA MURTHY

    2013-12-01

    Full Text Available This paper presents a novel high-speed and high-performance multiplexer based full adder cell for low-power applications. The proposed full adder is composed of two separate modules with identical hardware configurations that generate Sum and Carry signals in a parallel manner. The proposed adder circuit has an advantage in terms of short critical path when compared with various existing previous designs. Comprehensive experiments were performed in various situations to evaluate the performance of the proposed design. Simulations were performed by Microwind 2 VLSI CAD tool for LVS and BSIM 4 for parametric analysis of various feature sizes. The simulation results demonstrate clearly the improvement of the proposed design in terms of lower power dissipation, less propagation delay, less occupying area and low power delay product (PDP compared to other widely used existing full adder circuits.

  6. Application Delay Modelling for Variable Length Packets in Single Cell IEEE 802.11 WLANs

    CERN Document Server

    Sunny, Albert; Aggarwal, Saurabh

    2010-01-01

    In this paper, we consider the problem of modelling the average delay experienced by an application packets of variable length in a single cell IEEE 802.11 DCF wireless local area network. The packet arrival process at each node i is assumed to be a stationary and independent increment random process with mean ai and second moment a(2) i . The packet lengths at node i are assumed to be i.i.d random variables Pi with finite mean and second moment. A closed form expression has been derived for the same. We assume the input arrival process across queues to be uncorrelated Poison processes. As the nodes share a single channel, they have to contend with one another for a successful transmission. The mean delay for a packet has been approximated by modelling the system as a 1-limited Random Polling system with zero switchover times. Extensive simulations are conducted to verify the analytical results.

  7. A differential equation with state-dependent delay from cell population biology

    Science.gov (United States)

    Getto, Philipp; Waurick, Marcus

    2016-04-01

    We analyze a differential equation, describing the maturation of a stem cell population, with a state-dependent delay, which is implicitly defined via the solution of an ODE. We elaborate smoothness conditions for the model ingredients, in particular vital rates, that guarantee the existence of a local semiflow and allow to specify the linear variational equation. The proofs are based on theoretical results of Hartung et al. combined with implicit function arguments in infinite dimensions. Moreover we elaborate a criterion for global existence for differential equations with state-dependent delay. To prove the result we adapt a theorem by Hale and Lunel to the C1-topology and use a result on metric spaces from Diekmann et al.

  8. Correlation between induction of meiotic delay and aneuploidy in male mouse germ cells

    Energy Technology Data Exchange (ETDEWEB)

    Adler, I.D.; Gassner, P.; Schriever-Schwemmer, G.; Min, Zhou Ru [Institut fuer Sauugetiergenetik, Neuherberg (Germany)

    1993-12-31

    No aneuploidy assays are prescribed in any international guidelines for chemical safety testing up to now. The CEC-sponsored Aneuploidy Project has the aim to validate test methods for aneuploidy induction which could be used as screening tests. Furthermore, one of the major goals is to develop an understanding of mechanisms by which aneuploidy is induced. The present paper describes the investigation of meiotic delay and aneuploidy induction with the drug diazepam (DZ), the environmentally important mutagen acrylamide (AA) and the spindle poison colchicine (COL), which is used as a positive control. The time course of events was investigated. It is concluded that the assessment of meiotic delay can be used to preselect chemicals which require evaluation of aneuploidy induction during MMI in male germ cells.

  9. Discrimination between normal and cancer cells by using spectral analysis of delayed luminescence.

    Science.gov (United States)

    Musumeci, Francesco; Privitera, Giuseppe; Scordino, Agata; Tudisco, Salvatore; Lo Presti, Carmine; Applegate, Lee Ann; Niggli, Hugo J.

    2005-04-01

    In our present studies, the time-resolved emission spectrum of delayed luminescence of cell cultures of human fibroblast and human melanoma have been measured using a sophisticated single photon device. Noticeable differences have been found both in the emission spectra, which are time dependent, and in the timing aspects of the different spectral components. This powerful and noninvasive technique can be applied in all fields of skin research, such as the investigation of skin abnormalities and to test the effect of products involved in regeneration, antiaging, and UV-light protection in order to prevent skin cancer.

  10. FREQUENCY CATASTROPHE AND CO-EXISTING ATTRACTORS IN A CELL Ca2+ NONLINEAR OSCILLATION MODEL WITH TIME DELAY*

    Institute of Scientific and Technical Information of China (English)

    应阳君; 黄祖洽

    2001-01-01

    Frequency catastrophe is found in a cell Ca2+ nonlinear oscillation model with time delay. The relation of the frequency transition to the time delay is studied by numerical simulations and theoretical analysis. There is a range of parameters in which two kinds of attractors with great frequency differences co-exist in the system. Along with parameter changes, a critical phenomenon occurs and the oscillation frequency changes greatly. This mechanism helps us to deepen the understanding of the complex dynamics of delay systems, and might be of some meaning in cell signalling.

  11. The effect of ultraviolet radiation on the delayed type hypersensitivity using allogeneic epidermal cell antigens

    International Nuclear Information System (INIS)

    Low dose of ultraviolet B (UVB) radiation have been shown to impair the ability of epidermal cells (EC). We studied the effect of the UVB radiation on the delayed type hypersensitivity (DTH) induced by allogeneic EC. The DTH response was assayed by their footpad swelling. When EC were exposed to UVB radiation (660 J/m2), their ability to lead to TDTH activation was markedly inhibited in any combination of recipient mice and EC. The effect of UVB radiation on EC was observed before immunization and challenge. UVB treated EC did not induce suppressor T cells(Ts) in mice, which Ts might be induced by intravenous injection of EC. These results indicate that UVB radiation abrogates antigenicity of EC. (author)

  12. The radiation response of V79 and human tumour multicellular spheroids - cell survival and growth delay studies

    International Nuclear Information System (INIS)

    Chinese hamster cells (V79 379A), cells from a human small cell carcinoma of the lung (ME/MAR) and two xenografted human melanomas (HX117 and HX118) have been grown as multicellular spheroids in vitro. The radiation response of these four cell types has been compared when grown as spheroids (200 or 400 μm in diameter) and as single cells from disaggregated spheroids. The radiation sensitivity of the three human lines irradiated as single cells in air, is similar. In comparison, the V79 cells are more radioresistant. Only the V79 and HX118 cells show a spheroid size dependent radiation response. The radiation response of spheroids has been assayed using both cell survival and growth delay. V79, ME/MAR and HX117 cells demonstrate a good correlation between the two endpoints whereas with HX118 there appears to be greater cell kill for a given level of growth delay. This may be because HX118 is efficient in the repair of potentially lethal damage (PLD). The results support the view that extrinsic factors such as three dimensional contact, hypoxia and repair of PLD can be important and together with the intrinsic cell radiosensitivity will determine the radiation response of tumours. (author)

  13. Staphylococcus aureus-induced G2/M phase transition delay in host epithelial cells increases bacterial infective efficiency.

    Science.gov (United States)

    Alekseeva, Ludmila; Rault, Lucie; Almeida, Sintia; Legembre, Patrick; Edmond, Valérie; Azevedo, Vasco; Miyoshi, Anderson; Even, Sergine; Taieb, Frédéric; Arlot-Bonnemains, Yannick; Le Loir, Yves; Berkova, Nadia

    2013-01-01

    Staphylococcus aureus is a highly versatile, opportunistic pathogen and the etiological agent of a wide range of infections in humans and warm-blooded animals. The epithelial surface is its principal site of colonization and infection. In this work, we investigated the cytopathic effect of S. aureus strains from human and animal origins and their ability to affect the host cell cycle in human HeLa and bovine MAC-T epithelial cell lines. S. aureus invasion slowed down cell proliferation and induced a cytopathic effect, resulting in the enlargement of host cells. A dramatic decrease in the number of mitotic cells was observed in the infected cultures. Flow cytometry analysis revealed an S. aureus-induced delay in the G2/M phase transition in synchronous HeLa cells. This delay required the presence of live S. aureus since the addition of the heat-killed bacteria did not alter the cell cycle. The results of Western blot experiments showed that the G2/M transition delay was associated with the accumulation of inactive cyclin-dependent kinase Cdk1, a key inducer of mitosis entry, and with the accumulation of unphosphorylated histone H3, which was correlated with a reduction of the mitotic cell number. Analysis of S. aureus proliferation in asynchronous, G1- and G2-phase-enriched HeLa cells showed that the G2 phase was preferential for bacterial infective efficiency, suggesting that the G2 phase delay may be used by S. aureus for propagation within the host. Taken together, our results divulge the potential of S. aureus in the subversion of key cellular processes such as cell cycle progression, and shed light on the biological significance of S. aureus-induced host cell cycle alteration.

  14. Staphylococcus aureus-induced G2/M phase transition delay in host epithelial cells increases bacterial infective efficiency.

    Directory of Open Access Journals (Sweden)

    Ludmila Alekseeva

    Full Text Available Staphylococcus aureus is a highly versatile, opportunistic pathogen and the etiological agent of a wide range of infections in humans and warm-blooded animals. The epithelial surface is its principal site of colonization and infection. In this work, we investigated the cytopathic effect of S. aureus strains from human and animal origins and their ability to affect the host cell cycle in human HeLa and bovine MAC-T epithelial cell lines. S. aureus invasion slowed down cell proliferation and induced a cytopathic effect, resulting in the enlargement of host cells. A dramatic decrease in the number of mitotic cells was observed in the infected cultures. Flow cytometry analysis revealed an S. aureus-induced delay in the G2/M phase transition in synchronous HeLa cells. This delay required the presence of live S. aureus since the addition of the heat-killed bacteria did not alter the cell cycle. The results of Western blot experiments showed that the G2/M transition delay was associated with the accumulation of inactive cyclin-dependent kinase Cdk1, a key inducer of mitosis entry, and with the accumulation of unphosphorylated histone H3, which was correlated with a reduction of the mitotic cell number. Analysis of S. aureus proliferation in asynchronous, G1- and G2-phase-enriched HeLa cells showed that the G2 phase was preferential for bacterial infective efficiency, suggesting that the G2 phase delay may be used by S. aureus for propagation within the host. Taken together, our results divulge the potential of S. aureus in the subversion of key cellular processes such as cell cycle progression, and shed light on the biological significance of S. aureus-induced host cell cycle alteration.

  15. Induced mutations in tomato SlExp1 alter cell wall metabolism and delay fruit softening.

    Science.gov (United States)

    Minoia, Silvia; Boualem, Adnane; Marcel, Fabien; Troadec, Christelle; Quemener, Bernard; Cellini, Francesco; Petrozza, Angelo; Vigouroux, Jacqueline; Lahaye, Marc; Carriero, Filomena; Bendahmane, Abdelhafid

    2016-01-01

    Fruit ripening and softening are key traits for many fleshy fruit. Since cell walls play a key role in the softening process, expansins have been investigated to control fruit over ripening and deterioration. In tomato, expression of Expansin 1 gene, SlExp1, during fruit ripening was associated with fruit softening. To engineer tomato plants with long shelf life, we screened for mutant plants impaired in SlExp1 function. Characterization of two induced mutations, Slexp1-6_W211S, and Slexp1-7_Q213Stop, showed that SlExp1 loss of function leads to enhanced fruit firmness and delayed fruit ripening. Analysis of cell wall polysaccharide composition of Slexp1-7_Q213Stop mutant pointed out significant differences for uronic acid, neutral sugar and total sugar contents. Hemicelluloses chemistry analysis by endo-β-1,4-d-glucanase hydrolysis and MALDI-TOF spectrometry revealed that xyloglucan structures were affected in the fruit pericarp of Slexp1-7_Q213Stop mutant. Altogether, these results demonstrated that SlExp1 loss of function mutants yield firmer and late ripening fruits through modification of hemicellulose structure. These SlExp1 mutants represent good tools for breeding long shelf life tomato lines with contrasted fruit texture as well as for the understanding of the cell wall polysaccharide assembly dynamics in fleshy fruits.

  16. Coronatine inhibits stomatal closure and delays hypersensitive response cell death induced by nonhost bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Seonghee Lee

    2013-02-01

    Full Text Available Pseudomonas syringae is the most widespread bacterial pathogen in plants. Several strains of P. syringae produce a phytotoxin, coronatine (COR, which acts as a jasmonic acid mimic and inhibits plant defense responses and contributes to disease symptom development. In this study, we found that COR inhibits early defense responses during nonhost disease resistance. Stomatal closure induced by a nonhost pathogen, P. syringae pv. tabaci, was disrupted by COR in tomato epidermal peels. In addition, nonhost HR cell death triggered by P. syringae pv. tabaci on tomato was remarkably delayed when COR was supplemented along with P. syringae pv. tabaci inoculation. Using isochorismate synthase (ICS-silenced tomato plants and transcript profiles of genes in SA- and JA-related defense pathways, we show that COR suppresses SA-mediated defense during nonhost resistance.

  17. Delayed SCE frequency of rat bone marrow cells after radon inhalation

    International Nuclear Information System (INIS)

    Cytogenetic tests can reflect in vivo cellular modifications during development of induced neoplasic lesions. These last years, a new experimental in vivo cytogenetic test has been widely developed: Sister chromatid exchanges (SCE) especially on bone marrow cells. This study establishes the relationships between SCE in the bone marrow of rat and post exposure time following whole body neutron irradiation and radon inhalation. From the observed data a two stages response is pointed out. The first stage is thought to correspond to direct DNA damage and is characterized by a short term increase of bone marrow SCE followed by a rapid decrease up to the control values. The second one is marked by a delayed increase of SCE followed by a plateau significantly higher than the control values. From neutron radon exposure and from previously observed data this second stage strongly suggests a modification of the whole organism induced by 'mutagen/carcinogen' modified target organs

  18. Systemic treatment with CAR-engineered T cells against PSCA delays subcutaneous tumor growth and prolongs survival of mice

    International Nuclear Information System (INIS)

    Adoptive transfer of T cells genetically engineered with a chimeric antigen receptor (CAR) has successfully been used to treat both chronic and acute lymphocytic leukemia as well as other hematological cancers. Experimental therapy with CAR-engineered T cells has also shown promising results on solid tumors. The prostate stem cell antigen (PSCA) is a protein expressed on the surface of prostate epithelial cells as well as in primary and metastatic prostate cancer cells and therefore a promising target for immunotherapy of prostate cancer. We developed a third-generation CAR against PSCA including the CD28, OX-40 and CD3 ζ signaling domains. T cells were transduced with a lentivirus encoding the PSCA-CAR and evaluated for cytokine production (paired Student’s t-test), proliferation (paired Student’s t-test), CD107a expression (paired Student’s t-test) and target cell killing in vitro and tumor growth and survival in vivo (Log-rank test comparing Kaplan-Meier survival curves). PSCA-CAR T cells exhibit specific interferon (IFN)-γ and interleukin (IL)-2 secretion and specific proliferation in response to PSCA-expressing target cells. Furthermore, the PSCA-CAR-engineered T cells efficiently kill PSCA-expressing tumor cells in vitro and systemic treatment with PSCA-CAR-engineered T cells significantly delays subcutaneous tumor growth and prolongs survival of mice. Our data confirms that PSCA-CAR T cells may be developed for treatment of prostate cancer

  19. Increased expression of stefin B in the nucleus of T98G astrocytoma cells delays caspase activation

    Directory of Open Access Journals (Sweden)

    Tao eSun

    2012-09-01

    Full Text Available Stefin B (cystatin B is an endogenous inhibitor of cysteine proteinases localized in the nucleus and the cytosol. Loss-of-function mutations in the stefin B gene (CSTB gene were reported in patients with Unverricht-Lundborg disease (EPM1. Our previous results showed that thymocytes isolated from stefin B-deficient mice are more sensitive to apoptosis induced by the protein kinase C inhibitor staurosporin (STS than the wild-type control cells. We have also shown that the increased expression of stefin B in the nucleus of T98G astrocytoma cells delayed cell cycle progression through the S phase. In the present study we examined if the nuclear or cytosolic functions of stefin B are responsible for the accelerated induction of apoptosis observed in the cells from stefin B-deficient mice. We have shown that the overexpression of stefin B in the nucleus, but not in the cytosol of astrocytoma T98G cells, delayed caspase-3 and-7 activation. Pretreatment of cells with the pan-caspase inhibitor z-Val-Ala-Asp(OMe-fluoromethylketone completely inhibited caspase activation, while treatment with the inhibitor of calpains- and papain-like cathepsins (2S,3S-trans-epoxysuccinyl-leucylamido-3-methyl-butane ethyl ester did not prevent caspase activation. We concluded that the delay of caspase activation in T98G cells overexpressing stefin B in the nucleus is independent of cathepsin inhibition.

  20. Cell model of catecholaminergic polymorphic ventricular tachycardia reveals early and delayed afterdepolarizations.

    Directory of Open Access Journals (Sweden)

    Kirsi Kujala

    Full Text Available BACKGROUND: Induced pluripotent stem cells (iPSC provide means to study the pathophysiology of genetic disorders. Catecholaminergic polymorphic ventricular tachycardia (CPVT is a malignant inherited ion channel disorder predominantly caused by mutations in the cardiac ryanodine receptor (RyR2. In this study the cellular characteristics of CPVT are investigated and whether the electrophysiological features of this mutation can be mimicked using iPSC -derived cardiomyocytes (CM. METHODOLOGY/PRINCIPAL FINDINGS: Spontaneously beating CMs were differentiated from iPSCs derived from a CPVT patient carrying a P2328S mutation in RyR2 and from two healthy controls. Calcium (Ca(2+ cycling and electrophysiological properties were studied by Ca(2+ imaging and patch-clamp techniques. Monophasic action potential (MAP recordings and 24h-ECGs of CPVT-P2328S patients were analyzed for the presence of afterdepolarizations. We found defects in Ca(2+ cycling and electrophysiology in CPVT CMs, reflecting the cardiac phenotype observed in the patients. Catecholaminergic stress led to abnormal Ca(2+ signaling and induced arrhythmias in CPVT CMs. CPVT CMs also displayed reduced sarcoplasmic reticulum (SR Ca(2+ content, indicating leakage of Ca(2+ from the SR. Patch-clamp recordings of CPVT CMs revealed both delayed afterdepolarizations (DADs during spontaneous beating and in response to adrenaline and also early afterdepolarizations (EADs during spontaneous beating, recapitulating the changes seen in MAP and 24h-ECG recordings of patients carrying the same mutation. CONCLUSIONS/SIGNIFICANCE: This cell model shows aberrant Ca(2+ cycling characteristic of CPVT and in addition to DADs it displays EADs. This cell model for CPVT provides a platform to study basic pathology, to screen drugs, and to optimize drug therapy.

  1. High radiosensitivity of induction in contrast to radioresistance of expression of cells mediating delayed-type hypersensitivity during response to sheep red blood cells in mice

    International Nuclear Information System (INIS)

    The delayed-type hypersensitivity (DTH) reaction observed in mice primed i.v. with low doses of sheep red blood cells was greatly decreased when mice were irradiated with 300 rad before priming. An estimation of the radiosensitivity of DTH-mediating cells (DTH-C) was performed using a titration assay after local adoptive transfer of these cells mixed with antigen into the footpad of unprimed mice. A high radiosensitivity of the induction of DTH-C was observed with a D37 of approximately 50 rad. In contrast, the expression of DTH-C appeared radioresistant, as the D37 was approximately 2000 rad. (author)

  2. Pattern of hair cell loss and delayed peripheral neuron degeneration in inner ear by a high-dose intratympanic gentamicin

    Institute of Scientific and Technical Information of China (English)

    Jintao Yu; Dalian Ding; Fengjun Wang; Haiyan Jiang; Hong Sun; Richard Salvi

    2014-01-01

    To gain insights into the ototoxic effects of aminoglycoside antibiotics (AmAn) and delayed peripheral ganglion neuron death in the inner ear, experimental animal models were widely used with several different approaches including AmAn systemic injections, combination treat-ment of AmAn and diuretics, or local application of AmAn. In these approaches, systemic AmAn treatment alone usually causes incomplete damage to hair cells in the inner ear. Co-administration of diuretic and AmAn can completely destroy the cochlear hair cells, but it is impossible to damage the vestibular system. Only the approach of AmAn local application can selectively eliminate most sensory hair cells in the inner ear. Therefore, AmAn local application is more suitable for studies for complete hair cell destructions in cochlear and vestibular system and the following delayed peripheral ganglion neuron death. In current studies, guinea pigs were unilaterally treated with a high concentration of gentamicin (GM, 40 mg/ml) through the tympanic membrane into the middle ear cavity. Auditory functions and vestibular functions were measured before and after GM treatment. The loss of hair cells and delayed degeneration of ganglion neurons in both cochlear and vestibular system were quantified 30 days or 60 days after treatment. The results showed that both auditory and vestibular functions were completely abolished after GM treatment. The sensory hair cells were totally missing in the cochlea, and severely destroyed in vestibular end-organs. The delayed spiral ganglion neuron death 60 days after the deafening procedure was over 50%. However, no obvious pathological changes were observed in vestibular ganglion neurons 60 days post-treatment. These results indicated that a high concentration of gentamycin delivered to the middle ear cavity can destroy most sensory hair cells in the inner ear that subsequently causes the delayed spiral ganglion neuron degeneration. This model might be useful for studies

  3. The delayed rectifier, IKI, is the major conductance in type I vestibular hair cells across vestibular end organs

    Science.gov (United States)

    Ricci, A. J.; Rennie, K. J.; Correia, M. J.

    1996-01-01

    Hair cells were dissociated from the semicircular canal, utricle, lagena and saccule of white king pigeons. Type I hair cells were identified morphologically based on the ratios of neck width to cuticular plate width (NPR technique was used to measure electrical properties from type I hair cells. In voltage-clamp, the membrane properties of all identified type I cells were dominated by a predominantly outward potassium current, previously characterized in semicircular canal as IKI. Zero-current potential, activation, deactivation, slope conductance, pharmacologic and steady-state properties of the complex currents were not statistically different between type I hair cells of different vestibular end organs. The voltage dependence causes a significant proportion of this conductance to be active about the cell's zero-current potential. The first report of the whole-cell activation kinetics of the conductance is presented, showing a voltage dependence that could be best fit by an equation for a single exponential. Results presented here are the first data from pigeon dissociated type I hair cells from utricle, saccule and lagena suggesting that the basolateral conductances of a morphologically identified population of type I hair cells are conserved between functionally different vestibular end organs; the major conductance being a delayed rectifier characterized previously in semicircular canal hair cells as IKI.

  4. Inhibition of phosphatidylinositol 3-kinase promotes tumor cell resistance to chemotherapeutic agents via a mechanism involving delay in cell cycle progression

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Gail T.; Sullivan, Richard; Pare, Genevieve C.; Graham, Charles H., E-mail: grahamc@queensu.ca

    2010-11-15

    Approaches to overcome chemoresistance in cancer cells have involved targeting specific signaling pathways such as the phosphatidylinositol 3-kinase (PI3K) pathway, a stress response pathway known to be involved in the regulation of cell survival, apoptosis and growth. The present study determined the effect of PI3K inhibition on the clonogenic survival of human cancer cells following exposure to various chemotherapeutic agents. Treatment with the PI3K inhibitors LY294002 or Compound 15e resulted in increased survival of MDA-MB-231 breast carcinoma cells after exposure to doxorubicin, etoposide, 5-fluorouracil, and vincristine. Increased survival following PI3K inhibition was also observed in DU-145 prostate, HCT-116 colon and A-549 lung carcinoma cell lines exposed to doxorubicin. Increased cell survival mediated by LY294002 was correlated with a decrease in cell proliferation, which was linked to an increase in the proportion of cells in the G{sub 1} phase of the cell cycle. Inhibition of PI3K signaling also resulted in higher levels of the cyclin-dependent kinase inhibitors p21{sup Waf1/Cip1} and p27{sup Kip1}; and knockdown of p27{sup kip1} with siRNA attenuated resistance to doxorubicin in cells treated with LY294002. Incubation in the presence of LY294002 after exposure to doxorubicin resulted in decreased cell survival. These findings provide evidence that PI3K inhibition leads to chemoresistance in human cancer cells by causing a delay in cell cycle; however, the timing of PI3K inhibition (either before or after exposure to anti-cancer agents) may be a critical determinant of chemosensitivity.

  5. Pan-Bcl-2 inhibitor obatoclax delays cell cycle progression and blocks migration of colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Bruno Christian Koehler

    Full Text Available Despite the fact that new treatment regimes have improved overall survival of patients challenged by colorectal cancer (CRC, prognosis in the metastatic situation is still restricted. The Bcl-2 family of proteins has been identified as promising anti cancer drug target. Even though small molecules targeting Bcl-2 proteins are in clinical trials, little is known regarding their effects on CRC. The aim of this study was to preclinically investigate the value of ABT-737 and Obatoclax as anticancer drugs for CRC treatment. The effects of the BH3-mimetics ABT-737 and Obatoclax on CRC cells were assessed using viability and apoptosis assays. Wound healing migration and boyden chamber invasion assays were applied. 3-dimensional cell cultures were used for long term assessment of invasion and proliferation. Clinically relevant concentrations of pan-Bcl-2 inhibitor Obatoclax did not induce cell death. In contrast, the BH3-mimetic ABT-737 induced apoptosis in a dose dependent manner. Obatoclax caused a cell line specific slowdown of CRC cell growth. Furthermore, Obatoclax, but not ABT-737, recovered E-Cadherin expression and led to impaired migration and invasion of CRC cells. The proliferative capacity and invasiveness of CRC cells was strikingly inhibited by low dose Obatoclax in long term 3-dimensional cell cultures. Obatoclax, but not ABT-737, caused a G1-phase arrest accompanied by a downregulation of Cyclin D1 and upregulation of p27 and p21. Overexpression of Mcl-1, Bcl-xL or Bcl-2 reversed the inhibitory effect of Obatoclax on migration but failed to restore the proliferative capacity of Obatoclax-treated CRC cells. The data presented indicate broad and multifaceted antitumor effects of the pan-Bcl-2 inhibitor Obatoclax on CRC cells. In contrast to ABT-737, Obatoclax inhibited migration, invasion and proliferation in sublethal doses. In summary, this study recommends pan-Bcl-2 inhibition as a promising approach for clinical trials in CRC.

  6. Resveratrol-induced augmentation of telomerase activity delays senescence of endothelial progenitor cells

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-bin; ZHU Li; HUANG Jun; YIN Yi-gang; KONG Xiang-qing; RONG Qi-fei; SHI Ai-wu; CAO Ke-jiang

    2011-01-01

    Background Previous studies have shown that resveratrol increases endothelial progenitor cell (EPC) numbers and functional activity.Increased EPC numbers and activity are associated with the inhibition of EPC senescence.In this study,we investigated the effect of resveratrol on the senescence of EPCs,leading to potentiation of cellular function.Methods EPCs were isolated from human peripheral blood and identified immunocytochemically.EPCs were incubated with resveratrol (1,10,and 50 μmol/L) or control for specified times.After in vitro cultivation,acidic β-galactosidase staining revealed the extent of senescence in the cells.To gain further insight into the underlying mechanism of the effect of resveratrol,we measured telomerase activity using a polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA) technique.Furthermore,we measured the expression of human telomerase reverse transcriptase (hTERT) and the phosphorylation of Akt by immunoblotting.Results Resveratrol dose-dependently inhibited the onset of EPC senescence in culture.Resveratrol also significantly increased telomerase activity.Interestingly,quantitative real-time PCR analysis demonstrated that resveratrol dose-dependently increased the expression of the catalytic subunit,hTERT,an effect that was significantly inhibited by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers (wortmannin).The expression of hTERT is regulated by the PI3-K/Akt pathway; therefore,we examined the effect of resveratrol on Akt activity in EPCs.Immunoblotting analysis revealed that resveratrol led to dose-dependent phosphorylation and activation of Akt in EPCs.Conclusion Resveratrol delayed EPCs senescence in vitro,which may be dependent on telomerase activation.

  7. Low-dose formaldehyde delays DNA damage recognition and DNA excision repair in human cells.

    Directory of Open Access Journals (Sweden)

    Andreas Luch

    Full Text Available OBJECTIVE: Formaldehyde is still widely employed as a universal crosslinking agent, preservative and disinfectant, despite its proven carcinogenicity in occupationally exposed workers. Therefore, it is of paramount importance to understand the possible impact of low-dose formaldehyde exposures in the general population. Due to the concomitant occurrence of multiple indoor and outdoor toxicants, we tested how formaldehyde, at micromolar concentrations, interferes with general DNA damage recognition and excision processes that remove some of the most frequently inflicted DNA lesions. METHODOLOGY/PRINCIPAL FINDINGS: The overall mobility of the DNA damage sensors UV-DDB (ultraviolet-damaged DNA-binding and XPC (xeroderma pigmentosum group C was analyzed by assessing real-time protein dynamics in the nucleus of cultured human cells exposed to non-cytotoxic (<100 μM formaldehyde concentrations. The DNA lesion-specific recruitment of these damage sensors was tested by monitoring their accumulation at local irradiation spots. DNA repair activity was determined in host-cell reactivation assays and, more directly, by measuring the excision of DNA lesions from chromosomes. Taken together, these assays demonstrated that formaldehyde obstructs the rapid nuclear trafficking of DNA damage sensors and, consequently, slows down their relocation to DNA damage sites thus delaying the excision repair of target lesions. A concentration-dependent effect relationship established a threshold concentration of as low as 25 micromolar for the inhibition of DNA excision repair. CONCLUSIONS/SIGNIFICANCE: A main implication of the retarded repair activity is that low-dose formaldehyde may exert an adjuvant role in carcinogenesis by impeding the excision of multiple mutagenic base lesions. In view of this generally disruptive effect on DNA repair, we propose that formaldehyde exposures in the general population should be further decreased to help reducing cancer risks.

  8. Is Low Non-Lethal Concentration of Methylmercury Really Safe? A Report on Genotoxicity with Delayed Cell Proliferation

    Science.gov (United States)

    Crespo-Lopez, María Elena; Costa-Malaquias, Allan; Oliveira, Edivaldo H. C.; Miranda, Moysés S.; Arrifano, Gabriela P. F.; Souza-Monteiro, José R.; Sagica, Fernanda Espirito-Santo; Fontes-Junior, Enéas A.; Maia, Cristiane S. F.; Macchi, Barbarella M.; do Nascimento, José Luiz M.

    2016-01-01

    Human exposure to relatively low levels of methylmercury is worrying, especially in terms of its genotoxicity. It is currently unknown as to whether exposure to low levels of mercury (below established limits) is safe. Genotoxicity was already shown in lymphocytes, but studies with cells of the CNS (as the main target organ) are scarce. Moreover, disturbances in the cell cycle and cellular proliferation have previously been observed in neuronal cells, but no data are presently available for glial cells. Interestingly, cells of glial origin accumulate higher concentrations of methylmercury than those of neuronal origin. Thus, the aim of this work was to analyze the possible genotoxicity and alterations in the cell cycle and cell proliferation of a glioma cell line (C6) exposed to a low, non-lethal and non-apoptotic methylmercury concentration. Biochemical (mitochondrial activity) and morphological (integrity of the membrane) assessments confirmed the absence of cell death after exposure to 3 μM methylmercury for 24 hours. Even without promoting cell death, this treatment significantly increased genotoxicity markers (DNA fragmentation, micronuclei, nucleoplasmic bridges and nuclear buds). Changes in the cell cycle profile (increased mitotic index and cell populations in the S and G2/M phases) were observed, suggesting arrest of the cycle. This delay in the cycle was followed, 24 hours after methylmercury withdrawal, by a decrease number of viable cells, reduced cellular confluence and increased doubling time of the culture. Our work demonstrates that exposure to a low sublethal concentration of MeHg considered relatively safe according to current limits promotes genotoxicity and disturbances in the proliferation of cells of glial origin with sustained consequences after methylmercury withdrawal. This fact becomes especially important, since this cellular type accumulates more methylmercury than neurons and displays a vital role protecting the CNS, especially in

  9. Delayed expulsion of adult Trichinella spiralis by mast cell-deficient W/Wv mice.

    OpenAIRE

    Ha, T. Y.; Reed, N D; Crowle, P K

    1983-01-01

    Mast cell-deficient W/Wv mice and their mast cell-sufficient littermates were given infections of Trichinella spiralis. W/Wv mice were slower than their littermates to expel adult T. spiralis. Repair of the mast cell deficiency of W/Wv mice by bone marrow grafting was accompanied by accelerated expulsion of T. spiralis.

  10. The combination of valproic acid and lithium delays hematopoietic stem/progenitor cell differentiation.

    NARCIS (Netherlands)

    Walasek, M.A.; Bystrykh, L.; Boom, V. van den; Olthof, S.; Ausema, A.; Ritsema, M.; Huls, G.A.; Haan, G. de; Os, R. van

    2012-01-01

    Despite increasing knowledge on the regulation of hematopoietic stem/progenitor cell (HSPC) self-renewal and differentiation, in vitro control of stem cell fate decisions has been difficult. The ability to inhibit HSPC commitment in culture may be of benefit to cell therapy protocols. Small molecule

  11. The combination of valproic acid and lithium delays hematopoietic stem/progenitor cell differentiation

    NARCIS (Netherlands)

    Walasek, Marta A.; Bystrykh, Leonid; van den Boom, Vincent; Olthof, Sandra; Ausema, Albertina; Ritsema, Martha; Huls, Gerwin; de Haan, Gerald; van Os, Ronald

    2012-01-01

    Despite increasing knowledge on the regulation of hematopoietic stem/progenitor cell (HSPC) self-renewal and differentiation, in vitro control of stem cell fate decisions has been difficult. The ability to inhibit HSPC commitment in culture may be of benefit to cell therapy protocols. Small molecule

  12. Effect of ranitidine on postoperative suppression of natural killer cell activity and delayed hypersensitivity

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Pedersen, B K; Moesgaard, F;

    1989-01-01

    hypersensitivity (DTH) antigens, and blood drawn immediately before and 24 hours after skin incision was analyzed for spontaneous and in vitro stimulated (IL-2, IFN-alpha or indomethacin) natural killer (NK) cell activity and PHA and PPD-stimulated lymphocyte proliferation. Lymphocyte subsets (helper......-cell activity (p less than 0.02). Postoperative decrease in helper/inducer-T cell numbers was not significantly lessened (p = 0.07), and ranitidine did not influence the levels of suppressor-T cells. PHA and PPD responses in peripheral blood mononuclear cells were unaltered. The results may suggest potential...

  13. FACT prevents the accumulation of free histones evicted from transcribed chromatin and a subsequent cell cycle delay in G1.

    Directory of Open Access Journals (Sweden)

    Macarena Morillo-Huesca

    2010-05-01

    Full Text Available The FACT complex participates in chromatin assembly and disassembly during transcription elongation. The yeast mutants affected in the SPT16 gene, which encodes one of the FACT subunits, alter the expression of G1 cyclins and exhibit defects in the G1/S transition. Here we show that the dysfunction of chromatin reassembly factors, like FACT or Spt6, down-regulates the expression of the gene encoding the cyclin that modulates the G1 length (CLN3 in START by specifically triggering the repression of its promoter. The G1 delay undergone by spt16 mutants is not mediated by the DNA-damage checkpoint, although the mutation of RAD53, which is otherwise involved in histone degradation, enhances the cell-cycle defects of spt16-197. We reveal how FACT dysfunction triggers an accumulation of free histones evicted from transcribed chromatin. This accumulation is enhanced in a rad53 background and leads to a delay in G1. Consistently, we show that the overexpression of histones in wild-type cells down-regulates CLN3 in START and causes a delay in G1. Our work shows that chromatin reassembly factors are essential players in controlling the free histones potentially released from transcribed chromatin and describes a new cell cycle phenomenon that allows cells to respond to excess histones before starting DNA replication.

  14. A delayed hemolytic transfusion reaction after partial exchange transfusion for sickle cell disease in pregnancy: a case report and review of the literature.

    Science.gov (United States)

    Brumfield, C G; Huddleston, J F; DuBois, L B; Harris, B A

    1984-03-01

    A delayed hemolytic transfusion reaction that occurred after a prophylactic partial exchange transfusion for sickle-cell disease in pregnancy is described. The clinical presentation and laboratory findings of delayed transfusion reactions are discussed, with special emphasis on problems associated in the sickle-cell disease patient. Suggestions on how to minimize the risk of transfusion reactions in the pregnant sickle-cell disease patient are given. PMID:6700873

  15. Renal allograft rejection: examination of delayed differentiation of Treg and Th17 effector T cells.

    Science.gov (United States)

    Pekalski, Marcin; Jenkinson, Sarah E; Willet, Joseph D P; Poyner, Elizabeth F M; Alhamidi, Abdulaziz H; Robertson, Helen; Ali, Simi; Kirby, John A

    2013-03-01

    Antigen presentation after kidney transplantation occurs in lymphoid tissues remote from the allograft, with activated T cells then migrating towards the graft. This study examined the possibility that these activated T cells can differentiate to acquire Th17 or Treg phenotypes after a time consistent with their arrival within renal allograft tissues. An immunocytochemical study was performed to demonstrate the response to intragraft TGF-β and the phenotype of lymphoid cells within rejecting human renal allograft tissue. A series of in vitro experiments was then performed to determine the potential to induce these phenotypes by addition of appropriate cytokines 3days after initial T cell activation. During renal allograft rejection there was a strong response to TGF-β, and both FOXP3 and IL-17A were expressed by separate lymphoid cells in the graft infiltrate. FOXP3 could be induced to high levels by the addition of TGF-β1 3days after the initiation of allogeneic mixed leukocyte culture. This Treg marker was enriched in the sub-population of T cells expressing the cell-surface αE(CD103)β7 integrin. The RORγt transcription factor and IL-17A were induced 3days after T cell activation by the addition of TGF-β1, IL-1β, IL-6 and IL-23; many of these Th17 cells also co-expressed CD103. T cells can develop an effector phenotype following cytokine stimulation 3days after initial activation. This suggests that the intragraft T cell phenotype may be indicative of the prevailing cytokine microenvironment.

  16. Nucleolar re-activation is delayed in mouse embryos cloned from two different cell lines

    DEFF Research Database (Denmark)

    Svarcova, Olga; Dinnyes, A.; Polgar, Z.;

    2009-01-01

    Aim of this study was to evaluate and compare embryonic genome activation (EGA) in mouse embryos of different origin using nucleolus as a marker. Early and late 2-cell and late 4-cell stage embryos, prepared by in vitro fertilization (IVF), parthenogenetic activation (PG), and nuclear transfer...

  17. Genetic 'risk' for atopy is associated with delayed postnatal maturation of T-cell competence.

    Science.gov (United States)

    Holt, P G; Clough, J B; Holt, B J; Baron-Hay, M J; Rose, A H; Robinson, B W; Thomas, W R

    1992-12-01

    Recent in vitro studies suggest that IgE production in adults is co-ordinately regulated by negative signals from gamma IFN-producing CD4+ T-helper-1 (TH-1) and positive signals from IL-4 producing (TH-2) T-cells. Additionally, seroepidemiological evidence has pinpointed infancy as the period of maximum lifetime risk for T-cell sensitization to ubiquitous environmental antigens. The present study sought to elucidate the relationship between these observations, by examination of CD4+ T-cell function in normal children and those genetically at 'high risk' for atopy, spanning the age range (up to 4 years) in which IgE responses to environmental allergens is typically manifest. Immunocompetent T-cell precursor frequencies (determined by cloning at limiting dilution) were markedly reduced in 'high risk' children relative to normals (0.53 +/- 0.29 vs 0.26 +/- 0.19; P = 0.0025). Consistent with reports from other laboratories employing bulk T-cell culture techniques, the gamma IFN producing capacity of CD4+ T-cell clones from both groups of children were markedly reduced relative to adults, and was lowest in the high risk group (P early childhood occur against a background of maturational 'deficiency' in CD4+ T-cell function, and suggests the possibility that variations in the rate of postnatal maturation of T-cell competence may be a contributing factor in the development of differing patterns of immunological responsiveness to environmental allergens. PMID:1486538

  18. Relief of delayed oxidative stress by ascorbic acid can suppress radiation-induced cellular senescence in mammalian fibroblast cells.

    Science.gov (United States)

    Kobashigawa, Shinko; Kashino, Genro; Mori, Hiromu; Watanabe, Masami

    2015-03-01

    Ionizing radiation-induced cellular senescence is thought to be caused by nuclear DNA damage that cannot be repaired. However, here we found that radiation induces delayed increase of intracellular oxidative stress after irradiation. We investigated whether the relief of delayed oxidative stress by ascorbic acid would suppress the radiation-induced cellular senescence in Syrian golden hamster embryo (SHE) cells. We observed that the level of oxidative stress was drastically increased soon after irradiation, then declined to the level in non-irradiated cells, and increased again with a peak on day 3 after irradiation. We found that the inductions of cellular senescence after X-irradiation were reduced along with suppression of the delayed induction of oxidative stress by treatment with ascorbic acid, but not when oxidative stress occurred immediately after irradiation. Moreover, treatment of ascorbic acid inhibited p53 accumulation at 3 days after irradiation. Our data suggested a delayed increase of intracellular oxidative stress levels plays an important role in the process of radiation-induced cellular senescence by p53 accumulation.

  19. Quasi-Periodicity, Chaos and Coexistence in the Time Delay Controlled Two-Cell DC-DC Buck Converter

    Science.gov (United States)

    Koubaâ, Karama; Feki, Moez

    In addition to border collision bifurcation, the time delay controlled two-cell DC/DC buck converter is shown to exhibit a chaotic behavior as well. The time delay controller adds new design parameters to the system and therefore the variation of a parameter may lead to different types of bifurcation. In this work, we present a thorough analysis of different scenarios leading to bifurcation and chaos. We show that the time delay controlled two-cell DC/DC buck converter may also exhibit a Neimark-Sacker bifurcation which for some parameter set may lead to a 2D torus that may then break yielding a chaotic behavior. Besides, the saturation of the controller can also lead to the coexistence of a stable focus and a chaotic attractor. The results are presented using numerical simulation of a discrete map of the two-cell DC/DC buck converter obtained by expressing successive crossings of Poincaré section in terms of each other.

  20. Selected Activities of Citrus Maxima Merr. Fruits on Human Endothelial Cells: Enhancing Cell Migration and Delaying Cellular Aging

    OpenAIRE

    Paiwan Buachan; Linda Chularojmontri; Wattanapitayakul, Suvara K.

    2014-01-01

    Endothelial injury and damage as well as accumulated reactive oxygen species (ROS) in aging play a significant role in the development of cardiovascular disease (CVD). Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM) fruit extract on human umbilical vein endothelial cell (HUVECs) migration and aging. T...

  1. Effect of angiotensin Ⅱ type 1 receptor on delayed rectifier potassium current in catecholaminergic CATH.a cells

    Institute of Scientific and Technical Information of China (English)

    Jian-qing DU; Cheng-wen SUN; Jing-shi TANG

    2004-01-01

    AIM: To study the modulatory effects of angiotensin Ⅱ (Ang Ⅱ) on the delayed rectifier potassium (Kv) current(IKv) and its underlying intracellular mechanism in the catecholaminergic system of rats. METHODS: AT1 and AT2receptors of the differentiated and undifferentiated CATH.a cells were determined by radioligands binding assay.The IKv was recorded with the whole cell patch-clamp configuration in voltage clamp mode on CATH.a cells.RESULTS: The Ang Ⅱ receptor proteins including AT1 and AT2 receptors were expressed in CATH.a cells, and the number of the former was significantly more than the latter (P<0.01). The IKv of CATH.a cells was reduced by superfusion with the Ang Ⅱ (100 nmol/L) (P<0.05) in the presence of the AT2 receptor antagonist PD123319, but was not affected by only superfusion with PD123319. The effect of Ang Ⅱ on IKv in CATH.a cells was completely inhibited by addition of AT1 receptor antagonist losartan. Superfusion with Ang Ⅱ (100 nmol/L) plus U73122, an inhibitor of phospholipase C (PLC) in the presence of PD 123319 had no effect on the IKv [(20.2+2.8) pA/pF]. AngⅡ-induced reduction of IKv was attenuated (P<0.05) but not abolished by PKC inhibitor calphostin C (Cal) and selective CaMK Ⅱ inhibitor KN-93 (10 μmol/L) respectively. However, IKv reduction was completely abolished by superfusion with both Cal and KN-93. CONCLUSION: The inhibition of Kv currents in CATH.a cells by Ang Ⅱ is mediated by AT1 receptor, and the PLC, PKC and CaMK Ⅱ may be involved in signal transduction of AT1 receptor.The differentiated CATH.a cell is a useful cell model to study Ang Ⅱ receptor-mediated functional modulation of catecholaminergic system.

  2. Separation by column chromatography of cells active in delayed-onset hypersensitivities.

    Science.gov (United States)

    Godfrey, H P; Gell, P G

    1976-01-01

    Lymph node cells from guinea-pigs contact sensitive to 1-thiocyamo-2,4-dinitrobenzene have been fractionated by affinity chromatography over modified polyacrylamide beads. Cells mediating lymphokine release in response to active sensitizer were depleted only by chromatography over dinitrophyenyl (DNP) containing substrates and could be specifically eluted with DNP-glycine. DNP rosette-forming cells (RFC) were equally well depleted by chromatography using either DNP or trinitrophenyl containing materials but could not be eluted from the columns by DNP-glycine. While the antigen receptors of cells mediating the release of macrophage agglutination factor in response to DNP-containing antigens and of DNP-RFC were found to be hapten-specific, their specificity was shown to differ using chromatography over trinitrophenyl containing polyacrylamide. PMID:776818

  3. Rhinovirus infection induces cytotoxicity and delays wound healing in bronchial epithelial cells

    Directory of Open Access Journals (Sweden)

    Constantopoulos Andreas G

    2005-10-01

    Full Text Available Abstract Background Human rhinoviruses (RV, the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro. Methods Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxicity was assessed chromatometrically. Epithelial monolayers were mechanically wounded, exposed or not to RV and the repopulation of the damaged area was assessed by image analysis. Finally epithelial cell proliferation was assessed by quantitation of proliferating cell nuclear antigen (PCNA by flow cytometry. Results RV1b, RV5, RV7, RV14 and RV16 were able to induce considerable epithelial cytotoxicity, more pronounced in less dense cultures, in a cell-density and dose-dependent manner. RV9 was not cytotoxic. Furthermore, RV infection diminished the self-repair capacity of bronchial epithelial cells and reduced cell proliferation. Conclusion RV-induced epithelial cytotoxicity may become considerable in already compromised epithelium, such as in the case of asthma. The RV-induced impairment on epithelial proliferation and self-repair capacity may contribute to the development of airway remodeling.

  4. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice

    Science.gov (United States)

    Fu, Chun; Begum, Khurshida; Jordan, Philip W.; He, Yan; Overbeek, Paul A.

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2–3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line. PMID:27486799

  5. Ventral midbrain neural stem cells have delayed neurogenic potential in vitro.

    Science.gov (United States)

    Hegarty, Shane V; Spitere, Katie; Sullivan, Aideen M; O'Keeffe, Gerard W

    2014-01-24

    Neural stem cells (NSCs) have been the focus of an intensive effort to direct their differentiation in vitro towards desired neuronal phenotypes for cell replacement therapies. It is thought that NSCs derived from older embryos have limited neurogenic capacity and are restricted towards an astroglial fate. This idea is largely based on studies that typically analysed NSC-derived progeny following one week of in vitro differentiation. In this report, the neurogenic capacity of older ventral midbrain (VM) NSCs was assessed. When the older NSCs were differentiated for three weeks, there were significant increases in the numbers of newly born neurons at 14 and 21 days, as assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation. Therefore this study demonstrates that older NSCs retain significantly more neurogenic potential than was previously thought. These data have implications for NSC preparatory protocols and the choice of donor age for cell transplantation studies, and contributes to the understanding of NSC behaviour in vitro.

  6. The role of the bi-compartmental stem cell niche in delaying cancer

    Science.gov (United States)

    Shahriyari, Leili; Komarova, Natalia L.

    2015-10-01

    In recent years, by using modern imaging techniques, scientists have found evidence of collaboration between different types of stem cells (SCs), and proposed a bi-compartmental organization of the SC niche. Here we create a class of stochastic models to simulate the dynamics of such a heterogeneous SC niche. We consider two SC groups: the border compartment, S1, is in direct contact with transit-amplifying (TA) cells, and the central compartment, S2, is hierarchically upstream from S1. The S1 SCs differentiate or divide asymmetrically when the tissue needs TA cells. Both groups proliferate when the tissue requires SCs (thus maintaining homeostasis). There is an influx of S2 cells into the border compartment, either by migration, or by proliferation. We examine this model in the context of double-hit mutant generation, which is a rate-limiting step in the development of many cancers. We discover that this type of a cooperative pattern in the stem niche with two compartments leads to a significantly smaller rate of double-hit mutant production compared with a homogeneous, one-compartmental SC niche. Furthermore, the minimum probability of double-hit mutant generation corresponds to purely symmetric division of SCs, consistent with the literature. Finally, the optimal architecture (which minimizes the rate of double-hit mutant production) requires a large proliferation rate of S1 cells along with a small, but non-zero, proliferation rate of S2 cells. This result is remarkably similar to the niche structure described recently by several authors, where one of the two SC compartments was found more actively engaged in tissue homeostasis and turnover, while the other was characterized by higher levels of quiescence (but contributed strongly to injury recovery). Both numerical and analytical results are presented.

  7. Ultraviolet stress delays chromosome replication in light/dark synchronized cells of the marine cyanobacterium Prochlorococcus marinus PCC9511

    Directory of Open Access Journals (Sweden)

    Blot Nicolas

    2010-07-01

    Full Text Available Abstract Background The marine cyanobacterium Prochlorococcus is very abundant in warm, nutrient-poor oceanic areas. The upper mixed layer of oceans is populated by high light-adapted Prochlorococcus ecotypes, which despite their tiny genome (~1.7 Mb seem to have developed efficient strategies to cope with stressful levels of photosynthetically active and ultraviolet (UV radiation. At a molecular level, little is known yet about how such minimalist microorganisms manage to sustain high growth rates and avoid potentially detrimental, UV-induced mutations to their DNA. To address this question, we studied the cell cycle dynamics of P. marinus PCC9511 cells grown under high fluxes of visible light in the presence or absence of UV radiation. Near natural light-dark cycles of both light sources were obtained using a custom-designed illumination system (cyclostat. Expression patterns of key DNA synthesis and repair, cell division, and clock genes were analyzed in order to decipher molecular mechanisms of adaptation to UV radiation. Results The cell cycle of P. marinus PCC9511 was strongly synchronized by the day-night cycle. The most conspicuous response of cells to UV radiation was a delay in chromosome replication, with a peak of DNA synthesis shifted about 2 h into the dark period. This delay was seemingly linked to a strong downregulation of genes governing DNA replication (dnaA and cell division (ftsZ, sepF, whereas most genes involved in DNA repair (such as recA, phrA, uvrA, ruvC, umuC were already activated under high visible light and their expression levels were only slightly affected by additional UV exposure. Conclusions Prochlorococcus cells modified the timing of the S phase in response to UV exposure, therefore reducing the risk that mutations would occur during this particularly sensitive stage of the cell cycle. We identified several possible explanations for the observed timeshift. Among these, the sharp decrease in transcript levels

  8. EVI1 targets ΔNp63 and upregulates the cyclin dependent kinase inhibitor p21 independent of p53 to delay cell cycle progression and cell proliferation in colon cancer cells.

    Science.gov (United States)

    Nayak, Kasturi Bala; Kuila, Nivedita; Das Mohapatra, Alok; Panda, Aditya K; Chakraborty, Soumen

    2013-08-01

    Several lines of evidence suggest that specific transcriptional events are involved in cell cycle, proliferation and differentiation processes; however, their deregulation by proto-oncogenes are involved in the development of leukemia and tumors. One such proto-oncogene is ecotropic viral integration site I which can differentially effect cell cycle progression and proliferation, in cell types of different origin. Our data for the first time shows that ecotropic viral integration site I binds to ΔNp63 promoter element directly and down regulates its expression. Down regulation of ΔNp63 induces the expression of p21 in HT-29 cells and also in colon carcinoma cells that do not express p53 including patient samples expressing low level of p53, that eventually delay cell cycle progression at G0/G1 phase. Concomitant silencing of ecotropic viral integration site I from the cells or introduction of ΔNp63 to the cells significantly rescued this phenotype, indicating the growth defect induced by ΔNp63 deficiency to be, at least in part, attributable to ecotropic viral integration site I function. The mutual regulation between ecotropic viral integration site I and ΔNp63 may constitute a novel axis which might affect the downstream pathways in cells that do not express functional p53.

  9. Effect of ranitidine on postoperative suppression of natural killer cell activity and delayed hypersensitivity

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Pedersen, B K; Moesgaard, F;

    1989-01-01

    hypersensitivity (DTH) antigens, and blood drawn immediately before and 24 hours after skin incision was analyzed for spontaneous and in vitro stimulated (IL-2, IFN-alpha or indomethacin) natural killer (NK) cell activity and PHA and PPD-stimulated lymphocyte proliferation. Lymphocyte subsets (helper...

  10. Telomerase inhibition effectively targets mouse and human AML stem cells and delays relapse following chemotherapy

    DEFF Research Database (Denmark)

    Bruedigam, Claudia; Bagger, Frederik Otzen; Heidel, Florian H.;

    2014-01-01

    priority. Here, we show that targeting telomerase activity eradicates AML LSCs. Genetic deletion of the telomerase subunit Terc in a retroviral mouse AML model induces cell-cycle arrest and apoptosis of LSCs, and depletion of telomerase-deficient LSCs is partially rescued by p53 knockdown. Murine Terc...

  11. Can Full Duplex Boost Throughput and Delay of 5G Ultra-Dense Small Cell Networks?

    DEFF Research Database (Denmark)

    Gatnau, Marta; Berardinelli, Gilberto; Mahmood, Nurul Huda;

    2016-01-01

    Given the recent advances in system and antenna design, practical implementation of full duplex (FD) communication is becoming increasingly feasible. In this paper, the potential of FD in enhancing the performance of 5th generation (5G) ultra-dense small cell networks is investigated. The goal is...

  12. Iron oxide nanoparticles suppressed T helper 1 cell-mediated immunity in a murine model of delayed-type hypersensitivity

    Directory of Open Access Journals (Sweden)

    Shen CC

    2012-06-01

    Full Text Available Chien-Chang Shen,1,* Hong-Jen Liang,2,* Chia-Chi Wang,3 Mei-Hsiu Liao,4 Tong-Rong Jan11Department and Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, 2Innovation and Incubation Center, Yuanpei University, Hsinchu, 3School of Pharmacy, Kaohsiung Medical University, Kaohsiung, 4Division of Isotope Application, Institute of Energy Research, Taoyuan, Taiwan*These authors contributed equally to this workBackground: It was recently reported that iron oxide nanoparticles attenuated antigen-specific humoral responses and T cell cytokine expression in ovalbumin-sensitized mice. It is presently unclear whether iron oxide nanoparticles influence T helper 1 cell-mediated immunity. The present study aimed to investigate the effect of iron oxide nanoparticles on delayed-type hypersensitivity (DTH, whose pathophysiology requires the participation of T helper 1 cells and macrophages.Methods: DTH was elicited by a subcutaneous challenge with ovalbumin to the footpads of mice sensitized with ovalbumin. Iron oxide nanoparticles (0.2–10 mg iron/kg were administered intravenously 1 hour prior to ovalbumin sensitization. Local inflammatory responses were examined by footpad swelling and histological analysis. The expression of cytokines by splenocytes was measured by enzyme-linked immunosorbent assay.Results: Administration of iron oxide nanoparticles, in a dose-dependent fashion, significantly attenuated inflammatory reactions associated with DTH, including the footpad swelling, the infiltration of T cells and macrophages, and the expression of interferon-γ, interleukin-6, and tumor necrosis factor-α in the inflammatory site. Iron oxide nanoparticles also demonstrated a suppressive effect on ovalbumin-stimulated production of interferon-γ by splenocytes and the phagocytic activity of splenic CD11b+ cells.Conclusion: These results demonstrated that a single dose of iron oxide nanoparticles attenuated

  13. Expression of orphan G-protein coupled receptor GPR174 in CHO cells induced morphological changes and proliferation delay via increasing intracellular cAMP

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Kazuya; Yamamura, Chiaki; Tabata, Ken-ichi [Laboratory of Pharmacoinformatics, Graduate School of Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Fujita, Norihisa, E-mail: nori@ph.ritsumei.ac.jp [Laboratory of Pharmacoinformatics, Graduate School of Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); School of Pharmacy, Ristumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Expression of GPR174 in CHO cells induces morphological changes and proliferation delay. Black-Right-Pointing-Pointer These are due to increase in intracellular cAMP concentration. Black-Right-Pointing-Pointer Lysophosphatidylserine was identified to stimulate GPR174 leading to activate ACase. Black-Right-Pointing-Pointer The potencies of fatty acid moiety on LysoPS were oleoyl Greater-Than-Or-Slanted-Equal-To stearoyl > palmitoyl. Black-Right-Pointing-Pointer We propose that GPR174 is a lysophosphatidylserine receptor. -- Abstract: We established cell lines that stably express orphan GPCR GPR174 using CHO cells, and studied physiological and pharmacological features of the receptor. GPR174-expressing cells showed cell-cell adhesion with localization of actin filaments to cell membrane, and revealed significant delay of cell proliferation. Since the morphological changes of GPR174-cells were very similar to mock CHO cells treated with cholera toxin, we measured the concentration of intracellular cAMP. The results showed the concentration was significantly elevated in GPR174-cells. By measuring intracellular cAMP concentration in GPR174-cells, we screened lipids and nucleotides to identify ligands for GPR174. We found that lysophosphatidylserine (LysoPS) stimulated increase in intracellular cAMP in a dose-dependent manner. Moreover, phosphorylation of Erk was elevated by LysoPS in GPR174 cells. These LysoPS responses were inhibited by NF449, an inhibitor of G{alpha}{sub s} protein. These results suggested that GPR174 was a putative LysoPS receptor conjugating with G{alpha}{sub s}, and its expression induced morphological changes in CHO cells by constitutively activating adenylyl cycles accompanied with cell conjunctions and delay of proliferation.

  14. The delayed luminescence spectroscopy as tool to investigate the cytotoxic effect on human cancer cells of drug-loaded nanostructured lipid carrier

    Science.gov (United States)

    Grasso, R.; Gulino, M.; Scordino, A.; Musumeci, F.; Campisi, A.; Bonfanti, R.; Carbone, C.; Puglisi, G.

    2016-05-01

    The first results concerning the possibility to use Delayed Luminescence spectroscopy to evaluate the in vitro induction of cytotoxic effects on human glioblastoma cells of nanostructured lipid carrier and drug-loaded nanostructured lipid carrier are showed in this contribution. We tested the effects of nanostructured lipid carrier, ferulic acid and ferulic acidloaded nanostructured lipid carrier on U-87MG cell line. The study seems to confirm the ability of Delayed Luminescence to be sensible indicator of alterations induced on functionality of the mitochondrial respiratory chain complex I in U-87MG cancer cells when treated with nanostructured lipid carriers.

  15. The use of cell phones and radio communication systems to reduce delays in getting help for pregnant women in low- and middle-income countries: a scoping review

    Directory of Open Access Journals (Sweden)

    Sunday O. Oyeyemi

    2015-09-01

    Full Text Available Background: Delays in getting medical help are important factors in the deaths of many pregnant women and unborn children in the low- and middle-income countries (LMIC. Studies have suggested that the use of cell phones and radio communication systems might reduce such delays. Objectives: We review the literature regarding the impact of cell phones and radio communication systems on delays in getting medical help by pregnant women in the LMIC. Design: Cochrane Library, PubMed, Maternity and Infant care (Ovid, Web of Science (ISI, and Google Scholar were searched for studies relating to the use of cell phones for maternal and child health services, supplemented with hand searches. We included studies in LMIC and in English involving the simple use of cell phones (or radio communication to either make calls or send text messages. Results: Fifteen studies met the inclusion criteria. All the studies, while of various designs, demonstrated positive contributory effects of cell phones or radio communication systems in reducing delays experienced by pregnant women in getting medical help. Conclusions: While the results suggested that cell phones could contribute in reducing delays, more studies of a longer duration are needed to strengthen the finding.

  16. Rhinovirus infection induces cytotoxicity and delays wound healing in bronchial epithelial cells

    OpenAIRE

    Constantopoulos Andreas G; Skevaki Chrysanthi L; Gourgiotis Dimitrios; Psarras Stelios; Bossios Apostolos; Saxoni-Papageorgiou Photini; Papadopoulos Nikolaos G

    2005-01-01

    Abstract Background Human rhinoviruses (RV), the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro. Methods Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxic...

  17. Anti-apoptotic effect of morphine-induced delayed preconditioning on pulmonary artery endothelial cells with anoxia/reoxygenation injury

    Institute of Scientific and Technical Information of China (English)

    DING Weng-ang; ZHOU Hua-cheng; CUI Xiao-guang; LI Wen-zhi; GUO Yue-ping; ZHANG Bing; LIU Wei

    2008-01-01

    Background Opioid preconditioning (PC) reduces anoxiaJreoxygenation (NR) injury to various cells. However, it remains unclear whether opioid-induced delayed PC would show anti-apoptotic effects on pulmonary artery endothelial cells (PAECs) suffering from A/R injury. The present study was conducted to elucidate this issue and to investigate the potential mechanism of opioid-induced delayed PC.Methods Cultured porcine PAECs underwent 16-hour anoxia followed by 1-hour reoxygenation 24 hours after pretreatment with saline (NaCI; 0.9%) or morphine (1 μmol/L). To determine the underlying mechanism, a non-selective KATP channel inhibitor glibenclamide (Glib; 10 μmol/L), a nitric oxide (NO) synthase blocker NG-nitro-L-arginine methyl ester (L-NAME; 100 μmol/L), and an opioid receptor antagonist naloxone (Nal; 10 pmol/L) were given 30 minutes before the A/R load. The percentage of apoptotic cells was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, eNOS mRNA level was measured by real-time polymerase chain reaction (PCR). NO content of PAECs supernatants was measured with the Griess reagent.Results Compared to the A/R PAECs, morphine-induced delayed PC significantly reduced PAECs apoptosis ((18.1±1.9)% vs (5.5±0.3)%; P <0.05), increased NO release ((11.4±1.3) μmol/L vs (20.5±2.1) μmol/L, P <0.05), and up-regulated eNOS gene expression nearly 9 times (P<0.05). The anti-apoptosis effect of morphine was abolished by pretreatment with Glib, L-NAME and Nal, but the three agent-selves did not aggravate the A/R injury. Furthermore, L-NAME and Nal offset the enhanced release of NO caused by pretreatment with morphine.Conclusions Morphine-induced delayed PC prevents A/R injury of PAECs. This effect may be mediated by activation of KATP channel via opioid receptor and NO signaling pathways.

  18. Regulation of action potential delays via voltage-gated potassium Kv1.1 channels in dentate granule cells during hippocampal epilepsy

    Directory of Open Access Journals (Sweden)

    Florian eKirchheim

    2013-12-01

    Full Text Available Action potential (AP responses of dentate gyrus granule (DG cells have to be tightly regulated to maintain hippocampal function. However, which ion channels control the response delay of DG cells is not known. In some neuron types, spike latency is influenced by a dendrotoxin (DTX-sensitive delay current (ID mediated by unidentified combinations of voltage-gated K+ (Kv channels of the Kv1 family Kv1.1-6. In DG cells, the ID has not been characterized and its molecular basis is unknown. The response phenotype of mature DG cells is usually considered homogenous but intrinsic adaptations likely occur in particular in conditions of hyperexcitability, for example during temporal lobe epilepsy (TLE. In this study, we examined response delays of DG cells and underlying ion channel molecules by employing a new combination of gramicidin-perforated patch-clamp recordings in acute brain slices and single-cell reverse transcriptase quantitative polymerase chain reaction (SC RT-qPCR experiments. An in vivo mouse model of TLE consisting of intrahippocampal kainate (KA injection was used to examine epilepsy-related plasticity. Response delays of DG cells were DTX-sensitive and strongly increased in KA-injected hippocampi; Kv1.1 mRNA was elevated 10-fold, and the response delays correlated with Kv1.1 mRNA abundance on the single cell level. Other Kv1 subunits did not show overt changes in mRNA levels. Kv1.1 immunolabeling was enhanced in KA DG cells. The biophysical properties of ID and the delay heterogeneity between inner and outer DG cell layer were characterized. Using organotypic hippocampal slice cultures (OHCs, where KA incubation also induced ID upregulation, reversibility and neuroprotective potential for DG cells were tested. In summary, the AP timing of DG cells is effectively controlled via scaling of Kv1.1 subunit transcription. With this antiepileptic mechanism, DG cells delay their

  19. Autologous Bone Marrow Mononuclear Cell Transplantation Delays Progression of Carotid Atherosclerosis in Rabbits.

    Science.gov (United States)

    Cui, Kefei; Ma, Xiao; Yu, Lie; Jiang, Chao; Fu, Chao; Fu, Xiaojie; Yu, Xiaofang; Huang, Yuanjing; Hou, Suyun; Si, Caifeng; Chen, Zhengguang; Yu, Jing; Wan, Jieru; Wang, Jian

    2016-09-01

    Bone marrow mononuclear cells (BMMNCs) can counteract oxidative stress and inhibit the inflammatory response in focal ischemic stroke models. However, the effect of BMMNC transplantation on carotid atherosclerosis needs to be determined. The carotid atherosclerotic plaque model was established in New Zealand White rabbits by balloon injury and 8 weeks of high-fat diet. Rabbits were randomized to receive an intravenous injection of autologous bromodeoxyuridine (BrdU)-labeled BMMNCs or an equal volume of phosphate-buffered saline. Plaques were evaluated for expression of proinflammatory and anti-inflammatory cytokines, anti-oxidant proteins, and markers of cell death. BMMNCs migrated into atherosclerotic plaque on the first day after cell transplantation. BMMNC-treated rabbits had smaller plaques and more collagen deposition than did the vehicle-treated controls on day 28 (p < 0.05). BMMNC treatment significantly increased endothelial nitric oxide synthase and the anti-oxidant enzymes glutathione peroxidase and superoxide dismutase in plaques compared to vehicle treatment on day 7. BMMNC-treated rabbits also had lower levels of cleaved caspase-3 expression; lower levels of proinflammatory cytokines interleukin-1β, tumor necrosis factor alpha, and matrix metalloproteinase 9; and higher levels of insulin-like growth factor-1 and its receptor (p < 0.05). Autologous BMMNC transplantation can suppress the process of atherosclerotic plaque formation and is associated with enhanced anti-oxidative effect, reduced levels of inflammatory cytokines and cleaved caspase-3, and increased expression of insulin-like growth factor-1 and its receptor. BMMNC transplantation represents a novel approach for the treatment of carotid atherosclerosis. PMID:26232064

  20. Determination of radioinduced delay in DNA synthesis in two-garlic-clones cells (Allium Sativum L.)

    International Nuclear Information System (INIS)

    To contribute to tech improvement of the use of ionizing radiations as an auxiliary tool in the fitoimprovement, dose-effect curves for the 'Martinez' and 'Sancti Spiritus-3' clones were stablished by using as effect the delay induced by radiations in DNA synthesis determined by the 'Martinez' clone which induces a delay of 50% in reference to the control is approximately 11 Gy, while the dose value for the 'Sancti Spiritus-3' clone is 18 Gy, thus the 'Martinez' clones has a higher sensitivity to radiations than the other clone, therefore it coincides with what we found for these clones other indexes are used as radiosensitivity criteria

  1. Overexpression of the dynein light chain km23-1 in human ovarian carcinoma cells inhibits tumor formation in vivo and causes mitotic delay at prometaphase/metaphase.

    Science.gov (United States)

    Pulipati, Nageswara R; Jin, Qunyan; Liu, Xin; Sun, Baodong; Pandey, Manoj K; Huber, Jonathan P; Ding, Wei; Mulder, Kathleen M

    2011-08-01

    km23-1 is a dynein light chain that was identified as a TGFβ receptor-interacting protein. To investigate whether km23-1 controls human ovarian carcinoma cell (HOCC) growth, we established a tet-off inducible expression system in SKOV-3 cells in which the expression of km23-1 is induced upon doxycycline removal. We found that forced expression of km23-1 inhibited both anchorage-dependent and anchorage-independent growth of SKOV-3 cells. More importantly, induction of km23-1 expression substantially reduced the tumorigenicity of SKOV-3 cells in a xenograft model in vivo. Fluorescence-activated cell sorting analysis of SKOV-3 and IGROV-1 HOCCs demonstrated that the cells were accumulating at G2/M. Phospho-MEK, phospho-ERK and cyclin B1 were elevated, as was the mitotic index, suggesting that km23-1 suppresses HOCCs growth by inducing a mitotic delay. Immunofluorescence analyses demonstrated that the cells were accumulating at prometaphase/metaphase with increases in multipolar and multinucleated cells. Further, although the mitotic spindle assembly checkpoint protein BubR1 was present at the prometaphase kinetochore in Dox+/- cells, it was inappropriately retained at the metaphase kinetochore in Dox- cells. Thus, the mechanism by which high levels of km23-1 suppress ovarian carcinoma growth in vitro and inhibit ovary tumor formation in vivo appears to involve a BubR1-related mitotic delay.

  2. Reduced ultraviolet irradiation delays subsequent squamous cell carcinomas in hairless mice

    DEFF Research Database (Denmark)

    Togsverd-Bo, Katrine; Lerche, Catharina M; Poulsen, Thomas;

    2009-01-01

    time of appearance of the first skin tumor. RESULTS: The development of new tumors was delayed, corresponding to the degree of reductions in UV dose in an inversely linear manner. Discontinuation of UV doses delayed the median times to the second tumor by 24 days (2 SED, P = 0.0549) and 33.5 days (4...... tumors. The objective was to evaluate the significance of discontinued or reduced UV exposure for the development of subsequent skin tumors. METHODS: Seven groups of mice (n = 175) were irradiated with UV doses of 2 and 4 standard erythema doses (SED) that were continued, reduced or discontinued at the...... SED, P < 0.0001), and when reduced to 1 SED, the median delays were 18 days (2 SED, P = 0.0469) and 33 days (4 SED, P < 0.0001). The median delay to the third tumor was after UV reduction 47 days (4 SED, P < 0.0001) and 35 days (2 SED, P = 0.151), and after UV discontinuation 49 days (4 SED, P < 0...

  3. Clearance of p16(Ink4a)-positive senescent cells delays ageing-associated disorders

    NARCIS (Netherlands)

    Baker, Darren J.; Wijshake, Tobias; Tchkonia, Tamar; LeBrasseur, Nathan K.; Childs, Bennett G.; van de Sluis, Bart; Kirkland, James L.; van Deursen, Jan M.

    2011-01-01

    Advanced age is the main risk factor for most chronic diseases and functional deficits in humans, but the fundamental mechanisms that drive ageing remain largely unknown, impeding the development of interventions that might delay or prevent age-related disorders and maximize healthy lifespan. Cellul

  4. Clearance of p16Ink4a-positive senescent cells delays ageing-associated disorders

    NARCIS (Netherlands)

    Baker, D.J.; Wijshake, T.; Tchkonia, T.; LeBrasseur, N.K.; Childs, B.G.; Sluis, B. van de; Kirkland, J.L.; Deursen, J.M.A. van

    2011-01-01

    Advanced age is the main risk factor for most chronic diseases and functional deficits in humans, but the fundamental mechanisms that drive ageing remain largely unknown, impeding the development of interventions that might delay or prevent age-related disorders and maximize healthy lifespan. Cellul

  5. Subtotal tongue necrosis in delayed diagnosed giant-cell arteritis: a case report.

    Science.gov (United States)

    Biebl, Matthias Oliver; Hugl, Beate; Posch, Lydia; Tzankov, Alexandar; Weber, Florian; Perkmann, Reinhold; Fraedrich, Gustav

    2004-01-01

    Giant-cell arteritis (GCA) is a chronic systemic vasculitis of large- and medium-sized vessels, mainly affecting elderly patients. Headache, vision impairment, jaw claudication, and scalp tenderness are common symptoms. However, diagnosis can be difficult because GCA can affect almost every vascular pathway and lead to a variety of possible manifestations. We report the case of a belated diagnosed GCA, resulting in nearly complete necrosis of the mobile part of the tongue, visual impairment, and neurologic as well as intestinal ischemic symptoms. Aggressive immunosuppressive treatment resolved the symptoms, but the patient remained severely morbid because of bilateral necrosis of the mobile part of the tongue. In any case of unclear ischemic symptoms in an elderly patient, one must keep GCA in mind as the possible culprit disease.

  6. Delayed β-cell response and glucose intolerance in young women with Turner syndrome

    Directory of Open Access Journals (Sweden)

    Schmitz Ole

    2011-03-01

    Full Text Available Abstract Background To investigate glucose homeostasis in detail in Turner syndrome (TS, where impaired glucose tolerance (IGT and type 2 diabetes are frequent. Methods Cross sectional study of women with Turner syndrome (TS(n = 13 and age and body mass index matched controls (C (n = 13, evaluated by glucose tolerance (oral and intravenous glucose tolerance test (OGTT and IVGTT, insulin sensitivity (hyperinsulinemic, euglycemic clamp, beta-cell function (hyperglycaemic clamp, arginine and GLP-1 stimulation and insulin pulsatility. Results Fasting glucose and insulin levels were similar. Higher glucose responses was seen in TS during OGTT and IVGTT, persisting after correction for body weight or muscle mass, while insulin responses were similar in TS and C, despite the higher glucose level in TS, leading to an insufficient increase in insulin response during dynamic testing. Insulin sensitivity was comparable in the two groups (TS vs. control: 8.6 ± 1.8 vs. 8.9 ± 1.8 mg/kg*30 min; p = 0.6, and the insulin responses to dynamic β-cell function tests were similar. Insulin secretion patterns examined by deconvolution analysis, approximate entropy, spectral analysis and autocorrelation analysis were similar. In addition we found low IGF-I, higher levels of cortisol and norepinephrine and an increased waist-hip ratio in TS. Conclusions Young normal weight TS women show significant glucose intolerance in spite of normal insulin secretion during hyperglycaemic clamping and normal insulin sensitivity. We recommend regularly testing for diabetes in TS. Trial Registration Registered with http://clinicaltrials.com, ID nr: NCT00419107

  7. Delayed postoperative radiation therapy in local control of squamous cell carcinoma of the tongue and floor of the mouth

    International Nuclear Information System (INIS)

    Objective: to evaluate the effect of time between surgery and postoperative radiation therapy on local recurrence of squamous cell carcinoma of the tongue and floor of the mouth. Methods: a total of 154 patients treated between 1996 and 2007 were selected considering local recurrence rate and time of the adjuvant radiotherapy. Results: local recurrence was diagnosed in 54 (35%) patients. Radiation therapy reduced the rate of local recurrences, although with no statistical significance. The time between surgery and initiation of postoperative radiotherapy did not significantly influence the risk of local recurrence in patients referred to adjuvant treatment (p=0.49). Conclusion: in the presence of risk factors for local recurrence, a short delay in starting the adjuvant radiation therapy does not contraindicate its performance. (author)

  8. Optimizing the dynamics of a two-cell DC-DC buck converter by time delayed feedback control

    Science.gov (United States)

    Feki, M.; El Aroudi, A.; Robert, B. G. M.; Martínez-Salamero, L.

    2011-11-01

    A study of the dynamical behavior of a two-cell DC-DC buck converter under a digital time delayed feedback control (TDFC) is presented. Various numerical simulations and dynamical aspects of this system are illustrated in the time domain and in the parameter space. Without TDFC, the system may present many undesirable behaviors such as sub-harmonics and chaotic oscillations. TDFC is able to widen the stability range of the system. Optimum values of parameters giving rise to fast response while maintaining stable periodic behavior are given in closed form. However, it is detected that in a certain region of the parameter space, the stabilized periodic orbit may coexist with a chaotic attractor. Boundary between basins of attraction are obtained by means of numerical simulations.

  9. Delayed postoperative radiation therapy in local control of squamous cell carcinoma of the tongue and floor of the mouth

    Energy Technology Data Exchange (ETDEWEB)

    Amar, Ali; Chedid, Helma Maria; Curioni, Otavio Alberto; Rapoport, Abrao, E-mail: arapoport@uol.com.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Dedivitis, Rogerio Aparecido; Cernea, Claudio Roberto; Brandao, Lenine Garcia [Hospital Heliopolis, Sao aulo, SP (Brazil)

    2014-10-15

    Objective: to evaluate the effect of time between surgery and postoperative radiation therapy on local recurrence of squamous cell carcinoma of the tongue and floor of the mouth. Methods: a total of 154 patients treated between 1996 and 2007 were selected considering local recurrence rate and time of the adjuvant radiotherapy. Results: local recurrence was diagnosed in 54 (35%) patients. Radiation therapy reduced the rate of local recurrences, although with no statistical significance. The time between surgery and initiation of postoperative radiotherapy did not significantly influence the risk of local recurrence in patients referred to adjuvant treatment (p=0.49). Conclusion: in the presence of risk factors for local recurrence, a short delay in starting the adjuvant radiation therapy does not contraindicate its performance. (author)

  10. Computerized video time lapse study of cell cycle delay and arrest, mitotic catastrophe, apoptosis and clonogenic survival in irradiated 14-3-3sigma and CDKN1A (p21) knockout cell lines.

    Science.gov (United States)

    Chu, Kenneth; Teele, Noella; Dewey, Michael W; Albright, Norman; Dewey, William C

    2004-09-01

    Computerized video time lapse (CVTL) microscopy was used to observe cellular events induced by ionizing radiation (10-12 Gy) in nonclonogenic cells of the wild-type HCT116 colorectal carcinoma cell line and its three isogenic derivative lines in which p21 (CDKN1A), 14-3-3sigma or both checkpoint genes (double-knockout) had been knocked out. Cells that fused after mitosis or failed to complete mitosis were classified together as cells that underwent mitotic catastrophe. Seventeen percent of the wild-type cells and 34-47% of the knockout cells underwent mitotic catastrophe to enter generation 1 with a 4N content of DNA, i.e., the same DNA content as irradiated cells arrested in G(2) at the end of generation 0. Radiation caused a transient division delay in generation 0 before the cells divided or underwent mitotic catastrophe. Compared with the division delay for wild-type cells that express CDKN1A and 14-3-3sigma, knocking out CDKN1A reduced the delay the most for cells irradiated in G(1) (from approximately 15 h to approximately 3- 5 h), while knocking out 14-3-3sigma reduced the delay the most for cells irradiated in late S and G(2) (from approximately 18 h to approximately 3-4 h). However, 27% of wild-type cells and 17% of 14-3-3sigma(-/-) cells were arrested at 96 h in generation 0 compared with less than 1% for CDKN1A(-/-) and double-knockout cells. Thus expression of CDKN1A is necessary for the prolonged delay or arrest in generation 0. Furthermore, CDKN1A plays a crucial role in generation 1, greatly inhibiting progression into subsequent generations of both diploid cells and polyploid cells produced by mitotic catastrophe. Thus, in CDKN1A-deficient cell lines, a series of mitotic catastrophe events occurred to produce highly polyploid progeny during generations 3 and 4. Most importantly, the polyploid progeny produced by mitotic catastrophe events did not die sooner than the progeny of dividing cells. Death was identified as loss of cell movement, i

  11. Conditional deletion of Dicer in vascular smooth muscle cells leads to the developmental delay and embryonic mortality

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Yaoqian [Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Balazs, Louisa [Department of Pathology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Tigyi, Gabor [Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Yue, Junming, E-mail: yue@uthsc.edu [Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Center for Cancer Research, University of Tennessee Health Science Center, Memphis, TN 38163 (United States)

    2011-05-13

    Highlights: {yields} Deletion of Dicer in vascular smooth muscle cells(VSMCs) leads to embryonic mortality. {yields} Loss of Dicer in VSMCs leads to developmental delay. {yields} Loss of Dicer in VSMCs leads to hemorrhage in various organs including brain, skin and liver. {yields} Loss of Dicer in VSMCs leads to vascular wall remodeling. {yields} Loss of Dicer in VSMCs dysregulates the expression of miRNA and VSMC marker genes. -- Abstract: Dicer is a RNAase III enzyme that cleaves double stranded RNA and generates small interfering RNA (siRNA) and microRNA (miRNA). The goal of this study is to examine the role of Dicer and miRNAs in vascular smooth muscle cells (VSMCs). We deleted Dicer in VSMCs of mice, which caused a developmental delay that manifested as early as embryonic day E12.5, leading to embryonic death between E14.5 and E15.5 due to extensive hemorrhage in the liver, brain, and skin. Dicer KO embryos showed dilated blood vessels and a disarray of vascular architecture between E14.5 and E15.5. VSMC proliferation was significantly inhibited in Dicer KOs. The expression of VSMC marker genes were significantly downregulated in Dicer cKO embryos. The vascular structure of the yolk sac and embryo in Dicer KOs was lost to an extent that no blood vessels could be identified after E15.5. Expression of most miRNAs examined was compromised in VSMCs of Dicer KO. Our results indicate that Dicer is required for vascular development and regulates vascular remodeling by modulating VSMC proliferation and differentiation.

  12. The Hydrogen Sulfide Donor NaHS Delays Programmed Cell Death in Barley Aleurone Layers by Acting as an Antioxidant.

    Science.gov (United States)

    Zhang, Ying-Xin; Hu, Kang-Di; Lv, Kai; Li, Yan-Hong; Hu, Lan-Ying; Zhang, Xi-Qi; Ruan, Long; Liu, Yong-Sheng; Zhang, Hua

    2015-01-01

    H2S is a signaling molecule in plants and animals. Here we investigated the effects of H2S on programmed cell death (PCD) in barley (Hordeum vulgare L.) aleurone layers. The H2S donor NaHS significantly delayed PCD in aleurone layers isolated from imbibed embryoless barley grain. NaHS at 0.25 mM effectively reduced the accumulation of superoxide anion (·O2 (-)), hydrogen peroxide (H2O2), and malondialdehyde (MDA), promoted the activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and decreased those of lipoxygenase (LOX) in isolated aleurone layers. Quantitative-PCR showed that NaHS treatment of aleurone tissue led to enhanced transcript levels of the antioxidant genes HvSOD1, HvAPX, HvCAT1, and HvCAT2 and repressed transcript levels of HvLOX (lipoxygenase gene) and of two cysteine protease genes HvEPA and HvCP3-31. NaHS treatment in gibberellic acid- (GA-) treated aleurone layers also delayed the PCD process, reduced the content of ·O2 (-), and increased POD activity while decreasing LOX activity. Furthermore, α-amylase secretion in barley aleurone layers was enhanced by NaHS treatment regardless of the presence or absence of GA. These data imply that H2S acted as an antioxidant in delaying PCD and enhances α-amylase secretion regardless of the presence of GA in barley aleurone layers.

  13. The Hydrogen Sulfide Donor NaHS Delays Programmed Cell Death in Barley Aleurone Layers by Acting as an Antioxidant

    Directory of Open Access Journals (Sweden)

    Ying-Xin Zhang

    2015-01-01

    Full Text Available H2S is a signaling molecule in plants and animals. Here we investigated the effects of H2S on programmed cell death (PCD in barley (Hordeum vulgare L. aleurone layers. The H2S donor NaHS significantly delayed PCD in aleurone layers isolated from imbibed embryoless barley grain. NaHS at 0.25 mM effectively reduced the accumulation of superoxide anion (·O2-, hydrogen peroxide (H2O2, and malondialdehyde (MDA, promoted the activity of superoxide dismutase (SOD, guaiacol peroxidase (POD, catalase (CAT, and ascorbate peroxidase (APX, and decreased those of lipoxygenase (LOX in isolated aleurone layers. Quantitative-PCR showed that NaHS treatment of aleurone tissue led to enhanced transcript levels of the antioxidant genes HvSOD1, HvAPX, HvCAT1, and HvCAT2 and repressed transcript levels of HvLOX (lipoxygenase gene and of two cysteine protease genes HvEPA and HvCP3-31. NaHS treatment in gibberellic acid- (GA- treated aleurone layers also delayed the PCD process, reduced the content of ·O2-, and increased POD activity while decreasing LOX activity. Furthermore, α-amylase secretion in barley aleurone layers was enhanced by NaHS treatment regardless of the presence or absence of GA. These data imply that H2S acted as an antioxidant in delaying PCD and enhances α-amylase secretion regardless of the presence of GA in barley aleurone layers.

  14. Development of a Porcine Delayed Wound-Healing Model and Its Use in Testing a Novel Cell-Based Therapy

    International Nuclear Information System (INIS)

    Purpose: A delayed full-thickness wound-healing model was developed and used for examining the capacity of adipose-derived stem cells (ASCs), either alone or in platelet-rich fibrin gels, to promote healing. Methods and Materials: Four pigs received electron beam radiation to the dorsal skin surface. Five weeks after radiation, subcutaneous fat was harvested from nonirradiated areas and processed to yield ASCs. Two weeks later, 28 to 30 full-thickness 1.5-cm2 wounds were made in irradiated and nonirradiated skin. Wounds were treated with either saline solution, ASCs in saline solution, platelet-rich plasma (PRP) fibrin gel, ASCs in PRP, or non-autologous green fluorescence protein-labeled ASCs. Results: The single radiation dose produced a significant loss of dermal microvasculature density (75%) by 7 weeks. There was a significant difference in the rate of healing between irradiated and nonirradiated skin treated with saline solution. The ASCs in PRP-treated wounds exhibited a significant 11.2% improvement in wound healing compared with saline solution. Enhancement was dependent on the combination of ASCs and PRP, because neither ASCs nor PRP alone had an effect. Conclusions: We have created a model that simulates the clinically relevant late radiation effects of delayed wound healing. Using this model, we showed that a combination of ASCs and PRP improves the healing rates of perfusion-depleted tissues, possibly through enhancing local levels of growth factors.

  15. Cells and Tissue Interactions with Glycated Collagen and their Relevance to Delayed Diabetic Wound Healing

    OpenAIRE

    LIAO, HUIJUAN; Zakhaleva, Julia; Chen, Weiliam

    2009-01-01

    Dermal accumulation of advanced glycation end products (AGEs) has increasingly been implicated as the underlying cause of delayed diabetic wound healing. Devising an in vitro model to adequately mimic glycated tissues will facilitate investigation into the mechanism of glycation in conjunction with exploration of new approaches or improvement of current therapies for treating diabetic chronic wounds. Collagen matrices were artificially glycated and the presence of AGEs was demonstrated by imm...

  16. Clinical outcome of incidentally discovered small renal cell carcinoma after delayed surgery

    International Nuclear Information System (INIS)

    This study was undertaken to investigate the growth rate and clinical outcome of patients with a small renal mass (SRM) after delayed surgery. We reviewed the clinical records of 34 patients with SRMs ≤ 4 cm at diagnosis, who underwent delayed surgical intervention during surveillance from January 2000 to December 2011. Radiographic evaluations using computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed at least every 6 months, and the tumor size was determined at least twice. The mean follow-up time was 26.6 ± 18.6 months and mean tumor doubling time was 23.4 ± 16.0 months. Histopathological analysis revealed that 32 of the 34 patients were malignant in pT1aN0M0. Only one patient showed tumor recurrence, who subsequently died due to tumor progression. The growth rate of the small renal mass was slow in the majority of our patients. Delayed intervention does not have a detrimental effect on cancer-specific outcomes

  17. T-cell effector function and unresponsiveness in the murine lymphocytic choriomeningitis virus infection. II. Delayed-type hypersensitivity unresponsiveness reflects a defective differentiation from TD precursor to effector cell

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Marker, O

    1986-01-01

    An increase in the virus dose from 10(2) LD50 (low dose) to 10(4) LD50 (high dose) of lymphocytic choriomeningitis virus (LCMV) results in markedly delayed virus clearance, in spite of a potent cytotoxic T-cell (TC) response. However, virus-specific delayed-type hypersensitivity (DTH) reactivity...... is markedly depressed in high-dose mice, suggesting an association between DTH and virus clearance. When virus-primed memory cells are transferred, DTH reactivity as well as virus-clearing capacity is restored in high-dose mice, indicating that the virus is not present in a changed or concealed form. The role...... of T-cells mediating DTH (TD cells) in virus clearance was also studied by adoptive transfer to naive recipients. Here the high-dose primed cells did mediate virus clearance, although no DTH reaction was detectable 24-72 h after transfer. However, when footpad swelling was measured 96 h or more after...

  18. Abrogation of the capacity of delayed-type hypersensitivity responses to alloantigens by intravenous injection of neuraminidase-treated allogeneic cells

    International Nuclear Information System (INIS)

    BALB/c or C3H/He mice were inoculated i.v. with allogeneic spleen cells untreated or treated with neuraminidase. Appreciable or potent anti-allo-delayed-type hypersensitivity (DTH) responses were observed when mice were inoculated i.v. with untreated allogeneic cells or inoculated i.v. with those cells followed by s.c. immunization with untreated allogeneic cells. In contrast, i.v. inoculation of neuraminidase-treated allogeneic cells (presensitization) not only failed to induce any significant anti-allo-DTH responses but also abolished the capability of the animals to develop DTH responses after s.c. immunization, indicating the tolerance induction. This tolerance was alloantigen-specific, and rapidly inducible and long lasting. The induction of suppressor cell activity was demonstrated in tolerant mice. When spleen cells from such tolerant mice were transferred i.v. into 600 R x-irradiated syngeneic recipient mice alone or together with normal syngeneic spleen cells, these tolerant spleen cells themselves failed to induce DTH responses but did not exhibit suppressive effect on the generation of DTH responses induced by normal spleen cells cotransferred. These results indicate that i.v. administration of neuraminidase-treated allogeneic cells results in the induction of alloantigen-specific tolerance which is not always associated with the induction of suppressor cell activity but rather with the elimination or functional impairment of alloantigen-specific clones

  19. A Genotoxic Stress-Responsive miRNA, miR-574-3p, Delays Cell Growth by Suppressing the Enhancer of Rudimentary Homolog Gene in Vitro

    Directory of Open Access Journals (Sweden)

    Ken-ichi Ishikawa

    2014-02-01

    Full Text Available MicroRNA (miRNA is a type of non-coding RNA that regulates the expression of its target genes by interacting with the complementary sequence of the target mRNA molecules. Recent evidence has shown that genotoxic stress induces miRNA expression, but the target genes involved and role in cellular responses remain unclear. We examined the role of miRNA in the cellular response to X-ray irradiation by studying the expression profiles of radio-responsive miRNAs and their target genes in cultured human cell lines. We found that expression of miR-574-3p was induced in the lung cancer cell line A549 by X-ray irradiation. Overexpression of miR-574-3p caused delayed growth in A549 cells. A predicted target site was detected in the 3'-untranslated region of the enhancer of the rudimentary homolog (ERH gene, and transfected cells showed an interaction between the luciferase reporter containing the target sequences and miR-574-3p. Overexpression of miR-574-3p suppressed ERH protein production and delayed cell growth. This delay was confirmed by knockdown of ERH expression. Our study suggests that miR-574-3p may contribute to the regulation of the cell cycle in response to X-ray irradiation via suppression of ERH protein production.

  20. Human folliculin delays cell cycle progression through late S and G2/M-phases: effect of phosphorylation and tumor associated mutations.

    Directory of Open Access Journals (Sweden)

    Laura A Laviolette

    Full Text Available The Birt-Hogg-Dube disease occurs as a result of germline mutations in the human Folliculin gene (FLCN, and is characterized by clinical features including fibrofolliculomas, lung cysts and multifocal renal neoplasia. Clinical and genetic evidence suggest that FLCN acts as a tumor suppressor gene. The human cell line UOK257, derived from the renal cell carcinoma of a patient with a germline mutation in the FLCN gene, harbors a truncated version of the FLCN protein. Reconstitution of the wild type FLCN protein into UOK257 cells delays cell cycle progression, due to a slower progression through the late S and G2/M-phases. Similarly, Flcn (-/- mouse embryonic fibroblasts progress more rapidly through the cell cycle than wild type controls (Flcn (flox/flox. The reintroduction of tumor-associated FLCN mutants (FLCN ΔF157, FLCN 1-469 or FLCN K508R fails to delay cell cycle progression in UOK257 cells. Additionally, FLCN phosphorylation (on Serines 62 and 73 fluctuates throughout the cell cycle and peaks during the G2/M phase in cells treated with nocodazole. In keeping with this observation, the reintroduction of a FLCN phosphomimetic mutant into the UOK257 cell line results in faster progression through the cell cycle compared to those expressing the wild type FLCN protein. These findings suggest that the tumor suppression function of FLCN may be linked to its impact on the cell cycle and that FLCN phosphorylation is important for this activity. Additionally, these observations describe a novel in vitro assay for testing the functional significance of FLCN mutations and/or genetic polymorphisms.

  1. Bone marrow stromal cells elicit tissue sparing after acute but not delayed transplantation into the contused adult rat thoracic spinal cord.

    NARCIS (Netherlands)

    Tewarie, R.D.; Hurtado, A.; Ritfeld, G.J.; Rahiem, S.T.; Wendell, D.F.; Barroso, M.M.; Grotenhuis, J.A.; Oudega, M.

    2009-01-01

    Bone marrow stromal cells (BMSC) transplanted into the contused spinal cord may support repair by improving tissue sparing. We injected allogeneic BMSC into the moderately contused adult rat thoracic spinal cord at 15 min (acute) and at 3, 7, and 21 days (delayed) post-injury and quantified tissue s

  2. Evidence for Inhibitory Effects of Flupirtine, a Centrally Acting Analgesic, on Delayed Rectifier K+ Currents in Motor Neuron-Like Cells

    OpenAIRE

    Sheng-Nan Wu; Ming-Chun Hsu; Yu-Kai Liao; Fang-Tzu Wu; Yuh-Jyh Jong; Yi-Ching Lo

    2012-01-01

    Flupirtine (Flu), a triaminopyridine derivative, is a centrally acting, non-opiate analgesic agent. In this study, effects of Flu on K+ currents were explored in two types of motor neuron-like cells. Cell exposure to Flu decreased the amplitude of delayed rectifier K+ current (I K(DR)) with a concomitant raise in current inactivation in NSC-34 neuronal cells. The dissociation constant for Flu-mediated increase of I K(DR) inactivation rate was about 9.8  μ M. Neither linopirdine (10  μ M), NMD...

  3. bFGF-Regulating MAPKs Are Involved in High Glucose-Mediated ROS Production and Delay of Vascular Endothelial Cell Migration.

    Directory of Open Access Journals (Sweden)

    Zhong Xin Zhu

    Full Text Available High blood sugar is a symptom of diabetes mellitus (DM. Vascular endothelial cells (VECs directly contact the blood and are damaged when blood sugar levels are high. However, the molecular mechanism underlying this process remains elusive. To analyze the effects of DM on migration, we simulated DM by applying high glucose (HG to the human VEC. HG delayed cell migration and induced phosphorylation of MAPKs (JNK and ERK. By contrast, in presence of bFGF, cell migration was promoted and MAPK phosphorylation levels were reduced. Furthermore, treatment with JNK and ERK inhibitors rescued HG-mediated delay of cell migration. Molecular and cell biological studies demonstrated that HG increased ROS production, whereas treatment with bFGF or JNK/ERK inhibitors blocked HG-induced ROS accumulation. Addition of MnTMPyP, a ROS scavenger, reduced HG-induced ROS production and accelerated cell migration, suggesting that the influence of HG on bFGF-MAPK signaling causes accumulation of ROS, which in turn regulate cell migration. This is the first study to elucidate the molecular mechanism of HG-mediated VEC migration; these findings could facilitate the development of novel therapies for DM.

  4. Induction of suppression of delayed type hypersensitivity to herpes simplex virus by epidermal cells exposed to UV-irradiated urocanic acid in vivo

    International Nuclear Information System (INIS)

    Urocanic acid (UCA), the putative photoreceptor for ultraviolet radiation (UV)-induced suppression, undergoes a UV-dependent trans to cis isomerisation. Epidermal cells from mice painted with UCA, containing a known proportion of the cis-isomer, generate suppression of the delayed type hypersensitivity response to herpes simplex virus type 1 (HSV-1) when transferred to naive syngeneic recipients at the same time and site as infection with HSV-1. One T suppressor cell subset, of phenotype (Thy1+, L3T4+, Ly2-), is induced by the cis-UCA modified epidermal cell transfer. Flow cytometric analysis of the epidermal cells from skin treated with UV or cis-UCA indicates an overall reduction from normal in the number of cells expressing MHC Class II antigens, but no alteration in the number expressing I-J antigens

  5. Multiplex polymerase chain reaction analysis of UV-A- and UV-B-induced delayed and early mutations in V79 Chinese hamster cells.

    Science.gov (United States)

    Dahle, Jostein; Noordhuis, Paul; Stokke, Trond; Svendsrud, Debbie Hege; Kvam, Egil

    2005-01-01

    We previously reported that approximately 10% of V79 Chinese hamster fibroblast populations clonally derived from single cells immediately after irradiation with either ultraviolet B (UV-B, 290-320 nm, mainly 311 nm) or ultraviolet A (UV-A, 320-400 nm, mainly 350-390 nm) radiation exhibit genomic instability. The instability is revealed by relatively high mutation frequencies in the hypoxanthine phosphoribosyl transferase (hprt) gene up to 23 cell generations after irradiation. These delayed mutant clones exhibited higher levels of oxidative stress than normal cells. Therefore, persistently increased oxidative stress has been proposed as a mechanism for UV-induced genomic instability. This study investigates whether this mechanism is reflected in the deletion spectrum of delayed mutant clones. Eighty-eight percent of the delayed mutant clones derived from UV-A-irradiated populations were found to have total deletion of the hprt gene. Correspondingly, 81% of UV-A-induced early mutations (i.e. detected shortly after irradiation) also had total deletions. Among delayed UV-B-induced mutant clones, 23% had total deletions and 8% had deletion of one exon, whereas all early UV-B events were either point mutations or small deletions or insertions. In conclusion, the multiplex polymerase chain reaction deletion screen showed that there were explicit differences in the occurrence of large gene alterations between early and delayed mutations induced by UV-B radiation. For UV-A radiation the deletion spectra were similar for delayed and early mutations. UV-A radiation is, in contrast to UV-B radiation, only weakly absorbed by DNA and probably induces mutation almost solely via production of reactive oxygen species. Therefore, the present results support the hypothesis that persistent increase in oxidative stress is involved in the mechanism of UV-induced genomic instability.

  6. Usefulness of delayed scan of FDG PET for the diagnosis of lymph node metastasis in non-small cell lung cancer

    OpenAIRE

    Kato, Satoshi; Nambu, Atsushi; Araki, Tsutomu

    2016-01-01

    PURPOSE: The purpose of this study was to evaluate the usefulness of delayed scan of 18F fluorodeoxyglucose positron emission tomography (FDG-PET) for the diagnosis of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC).METHODS: The subjects were 92 patients with NSCLC, who were examined dual-timepoint FDG-PET. A total of 510 LN stations were evaluated histologically. The maximum standardized uptake values (SUV) of LN stations were measured at early and delayed phases on FDG-PET ...

  7. Inhibition of BCL-2 leads to increased apoptosis and delayed neuronal differentiation in human ReNcell VM cells in vitro.

    Science.gov (United States)

    Fröhlich, Michael; Jaeger, Alexandra; Weiss, Dieter G; Kriehuber, Ralf

    2016-02-01

    BCL-2 is a multifunctional protein involved in the regulation of apoptosis, cell cycle progression and neural developmental processes. Its function in the latter process is not well understood and needs further elucidation. Therefore, we characterized the protein expression kinetics of BCL-2 and associated regulatory proteins of the intrinsic apoptosis pathway during the process of neuronal differentiation in ReNcell VM cells with and without functional inhibition of BCL-2 by its competitive ligand HA14-1. Inhibition of BCL-2 caused a diminished BCL-2 expression and higher levels of cleaved BAX, activated Caspase-3 and cleaved PARP, all pro-apoptotic markers, when compared with untreated differentiating cells. In parallel, flow cytometric analysis of HA14-1-treated cells revealed a delayed differentiation into HuC/D+ neuronal cells when compared to untreated differentiating cells. In conclusion, BCL-2 possess a protective function in fully differentiated ReNcell VM cells. We propose that the pro-survival signaling of BCL-2 is closely connected with its stimulatory effects on neurogenesis of human neural progenitor cells.

  8. Multi-gene epigenetic silencing of tumor suppressor genes in T-cell lymphoma cells; delayed expression of the p16 protein upon reversal of the silencing

    DEFF Research Database (Denmark)

    Nagasawa, T; Zhang, Q; Raghunath, P N;

    2006-01-01

    To understand better T-cell lymphomagenesis, we examined promoter CpG methylation and mRNA expression of closely related genes encoding p16, p15, and p14 tumor suppressor genes in cultured malignant T-cells that were derived from cutaneous, adult type, and anaplastic lymphoma kinase (ALK)-express...

  9. Optogenetics reveal delayed afferent synaptogenesis on grafted human-induced pluripotent stem cell-derived neural progenitors.

    Science.gov (United States)

    Avaliani, Natalia; Sørensen, Andreas Toft; Ledri, Marco; Bengzon, Johan; Koch, Philipp; Brüstle, Oliver; Deisseroth, Karl; Andersson, My; Kokaia, Merab

    2014-12-01

    Reprogramming of somatic cells into pluripotency stem cell state has opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human-induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here, we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSCs), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem (lt-NES) cells, which are known to form primarily GABAergic neurons. When differentiated in OHSCs for 6 weeks, lt-NES cell-derived neurons displayed neuronal properties such as tetrodotoxin-sensitive sodium currents and action potentials (APs), as well as both spontaneous and evoked postsynaptic currents, indicating functional afferent synaptic inputs. The grafted cells had a distinct electrophysiological profile compared to host cells in the OHSCs with higher input resistance, lower resting membrane potential, and APs with lower amplitude and longer duration. To investigate the origin of synaptic afferents to the grafted lt-NES cell-derived neurons, the host neurons were transduced with Channelrhodopsin-2 (ChR2) and optogenetically activated by blue light. Simultaneous recordings of synaptic currents in grafted lt-NES cell-derived neurons using whole-cell patch-clamp technique at 6 weeks after grafting revealed limited synaptic connections from host neurons. Longer differentiation times, up to 24 weeks after grafting in vivo, revealed more mature intrinsic properties and extensive synaptic afferents from host neurons to the lt-NES cell-derived neurons, suggesting that these cells require extended time for differentiation

  10. A combination of chondroitinase ABC, glial cell line-derived neurotrophic factor, and Nogo A antibody delayed-release microspheres for the treatment of spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Yu Zhang; Yueming Song

    2011-01-01

    The purpose of this study was to evaluate the effect of poly(lactide-co-glycolic acid) delayed-release microspheres, which were prepared using glial cell line-derived neurotrophic factor (GDNF), on the delayed-release, controllability, and protection of GDNF activity. The present study is the first to combine chondroitinase ABC, GDNF, and Nogo A antibody delayed-release microspheres for the treatment of spinal cord injury. Results show that the combined therapy of chondroitinase ABC,GDNF, and Nogo A antibody microspheres can increase the immunoreaction of neurofilament 200in the injured spinal cord, and this therapeutic effect was better than chondroitinase ABC, GDNF, or Nogo A antibody microspheres administered singularly.

  11. Ionizing radiation accelerates Drp1-dependent mitochondrial fission, which involves delayed mitochondrial reactive oxygen species production in normal human fibroblast-like cells

    International Nuclear Information System (INIS)

    Highlights: ► We report first time that ionizing radiation induces mitochondrial dynamic changes. ► Radiation-induced mitochondrial fission was caused by Drp1 localization. ► We found that radiation causes delayed ROS from mitochondria. ► Down regulation of Drp1 rescued mitochondrial dysfunction after radiation exposure. -- Abstract: Ionizing radiation is known to increase intracellular level of reactive oxygen species (ROS) through mitochondrial dysfunction. Although it has been as a basis of radiation-induced genetic instability, the mechanism involving mitochondrial dysfunction remains unclear. Here we studied the dynamics of mitochondrial structure in normal human fibroblast like cells exposed to ionizing radiation. Delayed mitochondrial O2·- production was peaked 3 days after irradiation, which was coupled with accelerated mitochondrial fission. We found that radiation exposure accumulated dynamin-related protein 1 (Drp1) to mitochondria. Knocking down of Drp1 expression prevented radiation induced acceleration of mitochondrial fission. Furthermore, knockdown of Drp1 significantly suppressed delayed production of mitochondrial O2·-. Since the loss of mitochondrial membrane potential, which was induced by radiation was prevented in cells knocking down of Drp1 expression, indicating that the excessive mitochondrial fission was involved in delayed mitochondrial dysfunction after irradiation.

  12. Modeling the Effects of Vorinostat In Vivo Reveals both Transient and Delayed HIV Transcriptional Activation and Minimal Killing of Latently Infected Cells.

    Science.gov (United States)

    Ke, Ruian; Lewin, Sharon R; Elliott, Julian H; Perelson, Alan S

    2015-10-01

    Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recent clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Furthermore, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo.

  13. Alteration of the thymic T cell repertoire by rotavirus infection is associated with delayed type 1 diabetes development in non-obese diabetic mice.

    Directory of Open Access Journals (Sweden)

    Nicole L Webster

    Full Text Available Rotaviruses are implicated as a viral trigger for the acceleration of type 1 diabetes in children. Infection of adult non-obese diabetic (NOD mice with rotavirus strain RRV accelerates diabetes development, whereas RRV infection in infant NOD mice delays diabetes onset. In this study of infant mice, RRV titers and lymphocyte populations in the intestine, mesenteric lymph nodes (MLN and thymus of NOD mice were compared with those in diabetes-resistant BALB/c and C57BL/6 mice. Enhanced intestinal RRV infection occurred in NOD mice compared with the other mouse strains. This was associated with increases in the frequency of CD8αβ TCRαβ intraepithelial lymphocytes, and their PD-L1 expression. Virus spread to the MLN and T cell numbers there also were greatest in NOD mice. Thymic RRV infection is shown here in all mouse strains, often in combination with alterations in T cell ontogeny. Infection lowered thymocyte numbers in infant NOD and C57BL/6 mice, whereas thymocyte production was unaltered overall in infant BALB/c mice. In the NOD mouse thymus, effector CD4(+ T cell numbers were reduced by infection, whereas regulatory T cell numbers were maintained. It is proposed that maintenance of thymic regulatory T cell numbers may contribute to the increased suppression of inflammatory T cells in response to a strong stimulus observed in pancreatic lymph nodes of adult mice infected as infants. These findings show that rotavirus replication is enhanced in diabetes-prone mice, and provide evidence that thymic T cell alterations may contribute to the delayed diabetes onset following RRV infection.

  14. Evidence for Inhibitory Effects of Flupirtine, a Centrally Acting Analgesic, on Delayed Rectifier K+ Currents in Motor Neuron-Like Cells

    Directory of Open Access Journals (Sweden)

    Sheng-Nan Wu

    2012-01-01

    Full Text Available Flupirtine (Flu, a triaminopyridine derivative, is a centrally acting, non-opiate analgesic agent. In this study, effects of Flu on K+ currents were explored in two types of motor neuron-like cells. Cell exposure to Flu decreased the amplitude of delayed rectifier K+ current (IK(DR with a concomitant raise in current inactivation in NSC-34 neuronal cells. The dissociation constant for Flu-mediated increase of IK(DR inactivation rate was about 9.8 μM. Neither linopirdine (10 μM, NMDA (30 μM, nor gabazine (10 μM reversed Flu-induced changes in IK(DR inactivation. Addition of Flu shifted the inactivation curve of IK(DR to a hyperpolarized potential. Cumulative inactivation for IK(DR was elevated in the presence of this compound. Flu increased the amplitude of M-type K+ current (IK(M and produced a leftward shift in the activation curve of IK(M. In another neuronal cells (NG108-15, Flu reduced IK(DR amplitude and enhanced the inactivation rate of IK(DR. The results suggest that Flu acts as an open-channel blocker of delayed-rectifier K+ channels in motor neurons. Flu-induced block of IK(DR is unlinked to binding to NMDA or GABA receptors and the effects of this agent on K+ channels are not limited to its action on M-type K+ channels.

  15. Interference with Ca2+ release activated Ca2+ (CRAC) channel function delays T-cell arrest in vivo

    OpenAIRE

    Waite, Janelle C.; Vardhana, Santosh; Shaw, Patrick J.; Jang, Jung-Eun; McCarl, Christie-Ann; Cameron, Thomas O; Feske, Stefan; Dustin, Michael L

    2013-01-01

    Entry of lymphocytes into secondary lymphoid organs (SLOs) involves intravascular arrest and intracellular calcium ion ([Ca2+]i) elevation. TCR activation triggers increased [Ca2+]i and can arrest T-cell motility in vitro. However the requirement for [Ca2+]i elevation in arresting T cells in vivo has not been tested. Here, we have manipulated the Ca2+ release-activated Ca2+ (CRAC) channel pathway required for [Ca2+]i elevation in T cells through genetic deletion of stromal interaction molecul...

  16. Delayed Biosynthesis of Varicella-Zoster Virus Glycoprotein C: Upregulation by Hexamethylene Bisacetamide and Retinoic Acid Treatment of Infected Cells

    OpenAIRE

    Storlie, Johnathan; Jackson, Wallen; Hutchinson, Jennifer; Grose, Charles

    2006-01-01

    In the course of examining the trafficking pathways of varicella-zoster virus (VZV) glycoproteins gE, gI, gH, and gB, we discovered that all four are synthesized within 4 to 6 h postinfection (hpi) in cultured cells. Thereafter, they travel via the trans-Golgi network to the outer cell membrane. When we carried out a similar analysis on VZV gC, we observed little gC biosynthesis in the first 72 hpi. Further examination disclosed that gC was present in the inocula of infected cells, but no new...

  17. MiR-146b negatively regulates migration and delays progression of T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Correia, Nádia C; Fragoso, Rita; Carvalho, Tânia; Enguita, Francisco J; Barata, João T

    2016-01-01

    Previous results indicated that miR-146b-5p is downregulated by TAL1, a transcription factor critical for early hematopoiesis that is frequently overexpressed in T-cell acute lymphoblastic leukemia (T-ALL) where it has an oncogenic role. Here, we confirmed that miR-146b-5p expression is lower in TAL1-positive patient samples than in other T-ALL cases. Furthermore, leukemia T-cells display decreased levels of miR-146b-5p as compared to normal T-cells, thymocytes and other hematopoietic progenitors. MiR-146b-5p silencing enhances the in vitro migration and invasion of T-ALL cells, associated with increased levels of filamentous actin and chemokinesis. In vivo, miR-146b overexpression in a TAL1-positive cell line extends mouse survival in a xenotransplant model of human T-ALL. In contrast, knockdown of miR-146b-5p results in leukemia acceleration and decreased mouse overall survival, paralleled by faster tumor infiltration of the central nervous system. Our results suggest that miR-146b-5p is a functionally relevant microRNA gene in the context of T-ALL, whose negative regulation by TAL1 and possibly other oncogenes contributes to disease progression by modulating leukemia cell motility and disease aggressiveness. PMID:27550837

  18. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair ... body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  19. Spatiotemporal pattern of neuronal injury induced by DFP in rats: A model for delayed neuronal cell death following acute OP intoxication

    International Nuclear Information System (INIS)

    Organophosphate (OP) neurotoxins cause acute cholinergic toxicity and seizures resulting in delayed brain damage and persistent neurological symptoms. Testing novel strategies for protecting against delayed effects of acute OP intoxication has been hampered by the lack of appropriate animal models. In this study, we characterize the spatiotemporal pattern of cellular injury after acute intoxication with the OP diisopropylfluorophosphate (DFP). Adult male Sprague-Dawley rats received pyridostigmine (0.1 mg/kg, im) and atropine methylnitrate (20 mg/kg, im) prior to DFP (9 mg/kg, ip) administration. All DFP-treated animals exhibited moderate to severe seizures within minutes after DFP injection but survived up to 72 h. AChE activity was significantly depressed in the cortex, hippocampus, subcortical brain tissue and cerebellum at 1 h post-DFP injection and this inhibition persisted for up to 72 h. Analysis of neuronal injury by Fluoro-Jade B (FJB) labeling revealed delayed neuronal cell death in the hippocampus, cortex, amygdala and thalamus, but not the cerebellum, starting at 4 h and persisting until 72 h after DFP treatment, although temporal profiles varied between brain regions. At 24 h post-DFP injection, the pattern of FJB labeling corresponded to TUNEL staining in most brain regions, and FJB-positive cells displayed reduced NeuN immunoreactivity but were not immunopositive for astrocytic (GFAP), oligodendroglial (O4) or macrophage/microglial (ED1) markers, demonstrating that DFP causes a region-specific delayed neuronal injury mediated in part by apoptosis. These findings indicate the feasibility of this model for testing neuroprotective strategies, and provide insight regarding therapeutic windows for effective pharmacological intervention following acute OP intoxication. - Research highlights: → DFP induced neuronal FJB labeling starting at 4-8 h after treatment → The pattern of DFP-induced FJB labeling closely corresponded to TUNEL staining → FJB

  20. Depletion of Aurora-A in zebrafish causes growth retardation due to mitotic delay and p53-dependent cell death.

    Science.gov (United States)

    Jeon, Hee-Yeon; Lee, Hyunsook

    2013-03-01

    Aurora-A is a serine/threonine mitotic kinase that is required for centrosome maturation. Many cancer cells over-express Aurora-A, and several reports have suggested that Aurora-A has prognostic value in the clinical treatment of cancer. Therefore, inhibitors for Aurora-A kinase have been developed. However, studies on Aurora-A are largely performed in cancer cell lines and are sometimes controversial. For effective evaluation of Aurora-A inhibitors in cancer treatment, it is essential to understand its function at the organism level. Here, we report the crucial functions of Aurora-A in homeostasis of spindle organization in mitosis using zebrafish embryogenesis as a model system. Using morpholino technology, we show that depletion of Aurora-A in zebrafish embryogenesis results in short bent trunks, accompanied by growth retardation and eventual cell death. Live-imaging and immunofluorescence analyses of the embryos revealed that the developmental defects are due to problems in mitosis, manifested through monopolar and disorganized spindle formation. Aurora-A-depleted cells exhibited mitotic arrest with congression failure, leading to activation of the spindle assembly checkpoint. Cell death in the absence of Aurora-A was partially rescued by co-injection of the p53 morpholino, suggesting that apoptosis after Aurora-A depletion is p53-dependent. The clinical implications of these results relate to the indication that Aurora-A inhibitors may be effective towards cancers with intact p53.

  1. [Cell-mediated immunity and delayed hypersensitivity study in splenectomy patients: a comparative evaluation between IFN-gamma and skin tests].

    Science.gov (United States)

    Miniello, S; Jirillo, E; Urgesi, G; D'Abbicco, D; Tomasicchio, N; Bonomo, G M

    1999-01-01

    The authors of this paper attempt to indicate a feasible, easy-to-use and inexpensive instrument for daily assessing and monitoring of splenectomized subjects to see if they are immunocompromised. Skin tests which are considered easy and inexpensive, may be useful for immunological investigation if their effectiveness is considered equal to that of more difficult and expensive methods. They have also assessed the effectiveness of ST in the study of specific cell-mediated immunity in general and also in cases of delayed hypersensibility, comparatively to serum IFN gamma dosage. The latter is produced by Th1 lymphocytes and Natural Killer cells and is considered a reasonable indicator of cell-mediated immunity and Th1-related delayed hypersensibility. The results of this study confirm that ST is effective in 100% of all splenectomized patients compared to positivity of 60% for the compromise of the immunocompetent system revealed by serum IFN gamma dosage in the same sample of patients. In addition, the fundamental role of other cytokines was confirmed. These include IL-2 which is produced by Th1 lymphocytes and whose lack of results in splenectomized patients are immunocompromised. This is revealed not only by IFN gamma dosage but also by ST. PMID:10633837

  2. Development of a Resistance-like Phenotype to Sorafenib by Human Hepatocellular Carcinoma Cells Is Reversible and Can Be Delayed by Metronomic UFT Chemotherapy

    Directory of Open Access Journals (Sweden)

    Terence C. Tang

    2010-11-01

    Full Text Available Acquired resistance to antiangiogenic drugs, such as sorafenib, is a major clinical problem. We studied development of a resistance to sorafenib in new preclinical models of human hepatocellular carcinoma (HCC along with a strategy to delay such resistance—combination with metronomic chemotherapy. Three different xenograft models were studied using human Hep3B HCC cells, which are highly responsive to sorafenib, namely, orthotopic and subcutaneous transplant in severe combined immunodeficient mice, and an orthotopic transplant in nude mice. The complementary DNA for the β-subunit of human choriogonadotropin was transfected into HCC cells, and urine levels of the protein were monitored as a surrogate of tumor burden. Extended daily treatments, sometimes interrupted by a break period of 3 to 7 days to allow recovery from toxicity at sorafenib doses of 30 to 60 mg/kg, were maintained until and after evidence of tumor relapse. Initially responsive tumors seemed to develop a resistance-like phenotype after long-term daily treatment (e.g., >42 days at doses of 30 to 60 mg/kg. Transplantation of cell lines established from progressing tumors into new hosts showed that the resistant phenotype was not propagated. Furthermore, a regimen of daily metronomic uracil + tegafur (UFT, an oral 5-fluorouracil prodrug chemotherapy with a less toxic regimen of sorafenib (15 mg/kg per day significantly delayed the onset of resistance (>91 days. In conclusion, development of a resistance-like phenotype to sorafenib is reversible, and metronomic UFT plus sorafenib may be a promising and well-tolerated treatment for increasing efficacy by delaying emergence of such resistance.

  3. Changes from 1992 to 2002 in the pretreatment delay for patients with squamous cell carcinoma of larynx or pharynx: a Danish nationwide survey from DAHANCA

    DEFF Research Database (Denmark)

    Primdahl, Hanne; Nielsen, Anni Linnet; Larsen, Susanne;

    2006-01-01

    In Denmark, a general impression of prolonged pretreatment delay for patients with head and neck cancer led to a nationwide study of time spans from symptom debut over first health care contact to start of treatment. Charts of consecutive new patients with squamous cell carcinoma of the pharynx...... and larynx, seen at the five Danish oncology centers in January-April 1992 and 2002, respectively, were reviewed. Of the 288 patients identified, definitive treatment was radiotherapy in 264 cases, surgery in one case. Twenty-three patients had neither surgery nor radiotherapy. Total time from first health...

  4. Rabies virus cross-reactive murine T cell clones: analysis of helper and delayed-type hypersensitivity function.

    NARCIS (Netherlands)

    H. Bunschoten; B. Dietzschold; I.J.Th.M. Claassen (Ivo); R. Klapmuts; F. UytdeHaag; A.D.M.E. Osterhaus (Ab)

    1990-01-01

    textabstractThree T cell clones derived from rabies virus-immunized BALB/c mice were analysed for specificity and function. The clones proved to be broadly cross-reactive by responding to different rabies virus isolates (PM, ERA, CVS, HEP) and other representatives of the genus Lyssavirus, like the

  5. Conditional deletion of the Itgb4 integrin gene in Schwann cells leads to delayed peripheral nerve regeneration.

    NARCIS (Netherlands)

    Zee, C.E.E.M. van der; Kreft, M.; Beckers, G.; Kuipers, A.; Sonnenberg, A.

    2008-01-01

    Several different integrins participate in the complex interactions that promote repair of the peripheral nervous system. The role of the integrin alpha6beta4 in peripheral nerve regeneration was investigated in mice by cre-mediated deletion of the Itgb4 (beta4) gene in Schwann cells. After a crush

  6. Delayed administration of glial cell line-derived neurotrophic factor (GDNF) protects retinal ganglion cells in a pig model of acute retinal ischemia

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Klassen, Henry; Johansson, Ulrica Englund;

    2009-01-01

    This study investigates whether intravitreal administration of glial cell line-derived neurotrophic factor (GDNF) enhances survival of NeuN positive retinal cells in a porcine model of retinal ischemia. 16 pigs were subjected to an ischemic insult where intraocular pressure was maintained at 5 mm......Hg below mean arterial blood pressure for 2 h. The mean IOP during the ischemic insult was 79.5 mmHg (s.e.m. 2.1 mmHg, n = 15). Three days after the insult the pigs received an intravitreal injection of GDNF microspheres or blank microspheres. The pigs were evaluated by way of multifocal.......04-0.16) in eyes treated with blank microspheres, and 0.24 (95% CI: 0.18-0.32) and 0.23 (95% CI: 0.15-0.33) in eyes treated with GDNF microspheres. These differences were statistically significant (P

  7. Differential expression of alpha 4 integrins on effector memory T helper cells during Bordetella infections. Delayed responses in Bordetella pertussis.

    Directory of Open Access Journals (Sweden)

    Tuan M Nguyen

    Full Text Available Bordetella pertussis (B. pertussis is the causative agent of whooping cough, a respiratory disease that is reemerging worldwide. Mechanisms of selective lymphocyte trafficking to the airways are likely to be critical in the immune response to this pathogen. We compared murine infection by B. pertussis, B. parapertussis, and a pertussis toxin-deleted B. pertussis mutant (BpΔPTX to test the hypothesis that effector memory T-helper cells (emTh display an altered pattern of trafficking receptor expression in B. pertussis infection due to a defect in imprinting. Increased cell recruitment to the lungs at 5 days post infection (p.i. with B. parapertussis, and to a lesser extent with BpΔPTX, coincided with an increased frequency of circulating emTh cells expressing the mucosal-associated trafficking receptors α4β7 and α4β1 while a reduced population of these cells was observed in B. pertussis infection. These cells were highly evident in the blood and lungs in B. pertussis infection only at 25 days p.i. when B. parapertussis and BpΔPTX infections were resolved. Although at 5 days p.i., an equally high percentage of lung dendritic cells (DCs from all infections expressed maturation markers, this expression persisted only in B. pertussis infection at 25 days p.i. Furthermore, at 5 days p.i with B. pertussis, lung DCs migration to draining lymph nodes may be compromised as evidenced by decreased frequency of CCR7(+ DCs, inhibited CCR7-mediated in vitro migration, and fewer DCs in lung draining lymph nodes. Lastly, a reduced frequency of allogeneic CD4(+ cells expressing α4β1 was detected following co-culture with lung DCs from B. pertussis-infected mice, suggesting a defect in DC imprinting in comparison to the other infection groups. The findings in this study suggest that B. pertussis may interfere with imprinting of lung-associated trafficking receptors on T lymphocytes leading to extended survival in the host and a prolonged course of disease.

  8. Growth delay of human bladder cancer cells by Prostate Stem Cell Antigen downregulation is associated with activation of immune signaling pathways

    International Nuclear Information System (INIS)

    Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI) anchored protein expressed not only in prostate but also in pancreas and bladder cancer as shown by immunohistochemistry and mRNA analysis. It has been targeted by monoclonal antibodies in preclinical animal models and more recently in a clinical trial in prostate cancer patients. The biological role played in tumor growth is presently unknown. In this report we have characterized the contribution of PSCA expression to tumor growth. A bladder cell line was engineered to express a doxycycline (dox) regulated shRNA against PSCA. To shed light on the PSCA biological role in tumor growth, microarray analysis was carried out as a function of PSCA expression. Expression of gene set of interest was further analyzed by qPCR Down regulation of the PSCA expression was associated with reduced cell proliferation in vitro and in vivo. Mice bearing subcutaneous tumors showed a reduced tumor growth upon treatment with dox, which effectively induced shRNA against PSCA as revealed by GFP expression. Pathway analysis of deregulated genes suggests a statistical significant association between PSCA downregulation and activation of genes downstream of the IFNα/β receptor. These experiments established for the first time a correlation between the level of PSCA expression and tumor growth and suggest a role of PSCA in counteracting the natural immune response

  9. Evidence for inhibitory effects of flupirtine, a centrally acting analgesic, on delayed rectifier k(+) currents in motor neuron-like cells.

    Science.gov (United States)

    Wu, Sheng-Nan; Hsu, Ming-Chun; Liao, Yu-Kai; Wu, Fang-Tzu; Jong, Yuh-Jyh; Lo, Yi-Ching

    2012-01-01

    Flupirtine (Flu), a triaminopyridine derivative, is a centrally acting, non-opiate analgesic agent. In this study, effects of Flu on K(+) currents were explored in two types of motor neuron-like cells. Cell exposure to Flu decreased the amplitude of delayed rectifier K(+) current (I(K(DR))) with a concomitant raise in current inactivation in NSC-34 neuronal cells. The dissociation constant for Flu-mediated increase of I(K(DR)) inactivation rate was about 9.8 μM. Neither linopirdine (10 μM), NMDA (30 μM), nor gabazine (10 μM) reversed Flu-induced changes in I(K(DR)) inactivation. Addition of Flu shifted the inactivation curve of I(K(DR)) to a hyperpolarized potential. Cumulative inactivation for I(K(DR)) was elevated in the presence of this compound. Flu increased the amplitude of M-type K(+) current (I(K(M))) and produced a leftward shift in the activation curve of I(K(M)). In another neuronal cells (NG108-15), Flu reduced I(K(DR)) amplitude and enhanced the inactivation rate of I(K(DR)). The results suggest that Flu acts as an open-channel blocker of delayed-rectifier K(+) channels in motor neurons. Flu-induced block of I(K(DR)) is unlinked to binding to NMDA or GABA receptors and the effects of this agent on K(+) channels are not limited to its action on M-type K(+) channels. PMID:22888361

  10. A specific inhibitor of protein kinase CK2 delays gamma-H2Ax foci removal and reduces clonogenic survival of irradiated mammalian cells

    Directory of Open Access Journals (Sweden)

    Huber Peter E

    2011-02-01

    Full Text Available Abstract Background The protein kinase CK2 sustains multiple pro-survival functions in cellular DNA damage response and its level is tightly regulated in normal cells but elevated in cancers. Because CK2 is thus considered as potential therapeutic target, DNA double-strand break (DSB formation and rejoining, apoptosis induction and clonogenic survival was assessed in irradiated mammalian cells upon chemical inhibition of CK2. Methods MRC5 human fibroblasts and WIDR human colon carcinoma cells were incubated with highly specific CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB, or mock-treated, 2 hours prior to irradiation. DSB was measured by pulsed-field electrophoresis (PFGE as well as gamma-H2AX foci formation and removal. Apoptosis induction was tested by DAPI staining and sub-G1 flow cytometry, survival was quantified by clonogenic assay. Results TBB treatment did not affect initial DNA fragmention (PFGE; up to 80 Gy or foci formation (1 Gy. While DNA fragment rejoining (PFGE was not inhibited by the drug, TBB clearly delayed gamma-H2AX foci disappearence during postirradiation incubation. No apoptosis induction could be detected for up to 38 hours for both cell lines and exposure conditions (monotherapies or combination, but TBB treatment at this moderately toxic concentration of 20 μM (about 40% survival enhanced radiation-induced cell killing in the clonogenic assay. Conclusions The data imply a role of CK2 in gamma-H2AX dephosporylation, most likely through its known ability to stimulate PP2A phosphatase, rather than DSB rejoining. The slight but definite clonogenic radiosensitization by TBB does apparently not result from interference with an apoptosis suppression function of CK2 in these cells but could reflect inhibitor-induced uncoupling of DNA damage response decay from break ligation.

  11. Analysis of boundary point (break point) in Linear Delay Model for nanoscale VLSI standard cell library characterization at PVT corners

    CERN Document Server

    Agarwal, Gaurav Kumar

    2014-01-01

    In VLSI chip design flow, Static Timing Analysis (STA) is used for fast and accurate analysis of data-path delay. This process is fast because delay is picked from Look Up Tables (LUT) rather than conventional SPICE simulations. But accuracy of this method depends upon the underlying delay model with which LUT was characterized. Non Linear Delay Model (NLDM) based LUTs are quite common in industries. These LUT requires huge amount to time during characterization because of huge number of SPICE simulations done at arbitrary points. To improve this people proposed various other delay models like alpha-power and piecewise linear delay models. Bulusu et al proposed Linear Delay Model(LDM) which reduces LUT generation time to 50 percent. LDM divides delay curve w.r.t input rise time(trin) into two different region one is linear and other is non-linear. This boundary point between linear and non- linear region was called break point (trb). Linear region will be done if we simulate at only two points. This advantage...

  12. Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides

    Directory of Open Access Journals (Sweden)

    Voelker Hans

    2008-04-01

    Full Text Available Abstract Background Among the most prominent metabolic alterations in cancer cells are the increase in glucose consumption and the conversion of glucose to lactic acid via the reduction of pyruvate even in the presence of oxygen. This phenomenon, known as aerobic glycolysis or the Warburg effect, may provide a rationale for therapeutic strategies that inhibit tumour growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat enriched with omega-3 fatty acids and medium-chain triglycerides (MCT. Methods Twenty-four female NMRI nude mice were injected subcutaneously with tumour cells of the gastric adenocarcinoma cell line 23132/87. The animals were then randomly split into two feeding groups and fed either a ketogenic diet (KD group; n = 12 or a standard diet (SD group; n = 12 ad libitum. Experiments were ended upon attainment of the target tumor volume of 600 mm3 to 700 mm3. The two diets were compared based on tumour growth and survival time (interval between tumour cell injection and attainment of target tumour volume. Results The ketogenic diet was well accepted by the KD mice. The tumour growth in the KD group was significantly delayed compared to that in the SD group. Tumours in the KD group reached the target tumour volume at 34.2 ± 8.5 days versus only 23.3 ± 3.9 days in the SD group. After day 20, tumours in the KD group grew faster although the differences in mean tumour growth continued significantly. Importantly, they revealed significantly larger necrotic areas than tumours of the SD group and the areas with vital tumour cells appear to have had fewer vessels than tumours of the SD group. Viable tumour cells in the border zone surrounding the necrotic areas of tumours of both groups exhibited a glycolytic phenotype with expression of glucose transporter-1 and transketolase-like 1 enzyme. Conclusion Application of an unrestricted ketogenic diet enriched with omega-3 fatty acids and MCT

  13. Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides

    International Nuclear Information System (INIS)

    Among the most prominent metabolic alterations in cancer cells are the increase in glucose consumption and the conversion of glucose to lactic acid via the reduction of pyruvate even in the presence of oxygen. This phenomenon, known as aerobic glycolysis or the Warburg effect, may provide a rationale for therapeutic strategies that inhibit tumour growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat enriched with omega-3 fatty acids and medium-chain triglycerides (MCT). Twenty-four female NMRI nude mice were injected subcutaneously with tumour cells of the gastric adenocarcinoma cell line 23132/87. The animals were then randomly split into two feeding groups and fed either a ketogenic diet (KD group; n = 12) or a standard diet (SD group; n = 12) ad libitum. Experiments were ended upon attainment of the target tumor volume of 600 mm3 to 700 mm3. The two diets were compared based on tumour growth and survival time (interval between tumour cell injection and attainment of target tumour volume). The ketogenic diet was well accepted by the KD mice. The tumour growth in the KD group was significantly delayed compared to that in the SD group. Tumours in the KD group reached the target tumour volume at 34.2 ± 8.5 days versus only 23.3 ± 3.9 days in the SD group. After day 20, tumours in the KD group grew faster although the differences in mean tumour growth continued significantly. Importantly, they revealed significantly larger necrotic areas than tumours of the SD group and the areas with vital tumour cells appear to have had fewer vessels than tumours of the SD group. Viable tumour cells in the border zone surrounding the necrotic areas of tumours of both groups exhibited a glycolytic phenotype with expression of glucose transporter-1 and transketolase-like 1 enzyme. Application of an unrestricted ketogenic diet enriched with omega-3 fatty acids and MCT delayed tumour growth in a mouse xenograft model. Further

  14. Mucosal B Cells Are Associated with Delayed SIV Acquisition in Vaccinated Female but Not Male Rhesus Macaques Following SIVmac251 Rectal Challenge.

    Directory of Open Access Journals (Sweden)

    Iskra Tuero

    2015-08-01

    Full Text Available Many viral infections, including HIV, exhibit sex-based pathogenic differences. However, few studies have examined vaccine-related sex differences. We compared immunogenicity and protective efficacy of monomeric SIV gp120 with oligomeric SIV gp140 in a pre-clinical rhesus macaque study and explored a subsequent sex bias in vaccine outcome. Each immunization group (16 females, 8 males was primed twice mucosally with replication-competent Ad-recombinants encoding SIVsmH4env/rev, SIV239gag and SIV239nefΔ1-13 and boosted twice intramuscularly with SIVmac239 monomeric gp120 or oligomeric gp140 in MF59 adjuvant. Controls (7 females, 5 males received empty Ad and MF59. Up to 9 weekly intrarectal challenges with low-dose SIVmac251 were administered until macaques became infected. We assessed vaccine-induced binding, neutralizing, and non-neutralizing antibodies, Env-specific memory B cells and plasmablasts/plasma cells (PB/PC in bone marrow and rectal tissue, mucosal Env-specific antibodies, and Env-specific T-cells. Post-challenge, only one macaque (gp140-immunized remained uninfected. However, SIV acquisition was significantly delayed in vaccinated females but not males, correlated with Env-specific IgA in rectal secretions, rectal Env-specific memory B cells, and PC in rectal tissue. These results extend previous correlations of mucosal antibodies and memory B cells with protective efficacy. The gp140 regimen was more immunogenic, stimulating elevated gp140 and cyclic V2 binding antibodies, ADCC and ADCP activities, bone marrow Env-specific PB/PC, and rectal gp140-specific IgG. However, immunization with gp120, the form of envelope immunogen used in RV144, the only vaccine trial to show some efficacy, provided more significant acquisition delay. Further over 40 weeks of follow-up, no gp120 immunized macaques met euthanasia criteria in contrast to 7 gp140-immunized and 2 control animals. Although males had higher binding antibodies than females, ADCC

  15. M867, a novel selective inhibitor of caspase-3 enhances cell death and extends tumor growth delay in irradiated lung cancer models.

    Directory of Open Access Journals (Sweden)

    Kwang Woon Kim

    Full Text Available BACKGROUND: Lung cancer remains the leading cause of cancer death worldwide. Radioresistance of lung cancer cells results in unacceptable rate of loco-regional failure. Although radiation is known to induce apoptosis, our recent study showed that knockdown of pro-apoptotic proteins Bak and Bax resulted in an increase in autophagic cell death and lung cancer radiosensitivity in vitro. To further explore the potential of apoptosis inhibition as a way to sensitize lung cancer for therapy, we tested M867, a novel chemical and reversible caspase-3 inhibitor, in combination with ionizing radiation in vivo and in vitro. METHODS AND FINDINGS: M867 reduced clonogenic survival in H460 lung cancer cells (DER = 1.27, p = 0.007 compared to the vehicle-treated treated cells. We found that administration of M867 with ionizing radiation in an in vivo mouse hind limb lung cancer model was well tolerated, and produced a significant tumor growth delay compared to radiation alone. A dramatic decrease in tumor vasculature was observed with M867 and radiation using von Willebrand factor staining. In addition, Ki67 index showed >5-fold reduction of tumor proliferation in the combination therapy group, despite the reduced levels of apoptosis observed with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. Radiosensitizing effect of M867 through inhibiting caspases was validated using caspase-3/-7 double-knockout (DKO mouse embryonic fibroblasts (MEF cell model. Consistent with our previous study, autophagy contributed to the mechanism of increased cell death, following inhibition of apoptosis. In addition, matrigel assay showed a decrease in in vitro endothelial tubule formation during the M867/radiation combination treatment. CONCLUSIONS: M867 enhances the cytotoxic effects of radiation on lung cancer and its vasculature both in vitro and in vivo. M867 has the potential to prolong tumor growth delay by inhibiting tumor proliferation

  16. Detailed Analysis of Apoptosis and Delayed Luminescence of Human Leukemia Jurkat T Cells after Proton Irradiation and Treatments with Oxidant Agents and Flavonoids

    Directory of Open Access Journals (Sweden)

    Irina Baran

    2012-01-01

    Full Text Available Following previous work, we investigated in more detail the relationship between apoptosis and delayed luminescence (DL in human leukemia Jurkat T cells under a wide variety of treatments. We used menadione and hydrogen peroxide to induce oxidative stress and two flavonoids, quercetin, and epigallocatechin gallate, applied alone or in combination with menadione or H2O2. 62 MeV proton beams were used to irradiate cells under a uniform dose of 2 or 10 Gy, respectively. We assessed apoptosis, cell cycle distributions, and DL. Menadione, H2O2 and quercetin were potent inducers of apoptosis and DL inhibitors. Quercetin decreased clonogenic survival and the NAD(PH level in a dose-dependent manner. Proton irradiation with 2 Gy but not 10 Gy increased the apoptotic rate. However, both doses induced a substantial G2/M arrest. Quercetin reduced apoptosis and prolonged the G2/M arrest induced by radiation. DL spectroscopy indicated that proton irradiation disrupted the electron flow within Complex I of the mitochondrial respiratory chain, thus explaining the massive necrosis induced by 10 Gy of protons and also suggested an equivalent action of menadione and quercetin at the level of the Fe/S center N2, which may be mediated by their binding to a common site within Complex I, probably the rotenone-binding site.

  17. Testosterone delays vascular smooth muscle cell senescence and inhibits collagen synthesis via the Gas6/Axl signaling pathway.

    Science.gov (United States)

    Chen, Yan-Qing; Zhao, Jing; Jin, Cheng-Wei; Li, Yi-Hui; Tang, Meng-Xiong; Wang, Zhi-Hao; Zhang, Wei; Zhang, Yun; Li, Li; Zhong, Ming

    2016-06-01

    Testosterone deficiency is associated with a higher incidence of cardiovascular diseases in men. However, its effect on cell senescence, which plays a causal role in vascular aging, remains unclear. Here, we tested the hypothesis that testosterone alleviated vascular smooth muscle cell (VSMC) senescence and collagen synthesis via growth arrest-specific protein 6 (Gas6)/Axl- and Akt/FoxO1a-dependent pathways. Testosterone significantly ameliorated angiotensin II-induced VSMC senescence and collagen overexpression. In addition, testosterone inhibited angiotensin II-induced matrix metalloproteinase-2 (MMP-2) activity, which played a pivotal role in facilitating age-related collagen deposition. Testosterone increased the expression of tissue inhibitor of metalloproteinase-2 but decreased the expression of MMP-2 and membrane type-1 metalloproteinase which contributed to increase MMP-2 activity. The effects on VSMCs senescence and collagen synthesis were mediated by restoration of angiotensin II-induced downregulation of Gas6 and Axl expression and a subsequent reduction of Akt and FoxO1a phosphorylation. The effects of testosterone were reversed by a Gas6 blocker, Axl-Fc, and a specific inhibitor of Axl, R428. Treatment of VSMCs with PI3K inhibitor LY294002 abrogated the downregulating effect of testosterone on MMP-2 activity. Furthermore, when FoxO1a expression was silenced by using a specific siRNA, the inhibitory effect of testosterone on MMP-2 activity was revered as well, that indicated this process was Akt/FoxO1a dependence. Taken together, Gas6/Axl and Akt/FoxO1a were involved in protective effects of testosterone on VSMCs senescence and collagen synthesis. Our results provide a novel mechanism underlying the protective effect of testosterone on vascular aging and may serve as a theoretical basis for testosterone replacement therapy. PMID:27206970

  18. Modifying effect of reduced glutathione on X-ray-induced chromosome aberration and cell-cycle delay in muntjac lymphocytes in vitro

    International Nuclear Information System (INIS)

    Reduced glutathione treatment to unstimulated lymphocytes of Muntiacus muntjak 30 min prior to X-irradiation (2, 3 and 4 Gy) reduced the frequency of production of deletions in all the doses of X-ray and that of dicentrics and rings in 3- and 4-Gy exposed cultures. The consistency and degree of protection was more in the case of deletions than dicentrics and rings, and this may be correlated with the dominance in the production of deletions in the muntjac system which might probably be due to either the low chromosome number or a less efficient DNA repair. GSH pretreatment also reduced the radiation-induced cell-cycle delay in 2-Gy exposed cultures almost to the normal level of kinetics. (Auth.)

  19. Changes from 1992 to 2002 in the pretreatment delay for patients with squamous cell carcinoma of larynx or pharynx: a Danish nationwide survey from DAHANCA

    DEFF Research Database (Denmark)

    Primdahl, Hanne; Nielsen, Anni Linnet; Larsen, Susanne;

    2006-01-01

    In Denmark, a general impression of prolonged pretreatment delay for patients with head and neck cancer led to a nationwide study of time spans from symptom debut over first health care contact to start of treatment. Charts of consecutive new patients with squamous cell carcinoma of the pharynx...... and larynx, seen at the five Danish oncology centers in January-April 1992 and 2002, respectively, were reviewed. Of the 288 patients identified, definitive treatment was radiotherapy in 264 cases, surgery in one case. Twenty-three patients had neither surgery nor radiotherapy. Total time from first health...... care contact to start of definitive treatment was significantly longer in 2002 than in 1992 (median 70 versus 50 days, p...

  20. A cytomegalovirus-based vaccine expressing a single tumor-specific CD8+ T-cell epitope delays tumor growth in a murine model of prostate cancer.

    Science.gov (United States)

    Klyushnenkova, Elena N; Kouiavskaia, Diana V; Parkins, Christopher J; Caposio, Patrizia; Botto, Sara; Alexander, Richard B; Jarvis, Michael A

    2012-06-01

    Cytomegalovirus (CMV) is a highly immunogenic virus that results in a persistent, life-long infection in the host typically with no ill effects. Certain unique features of CMV, including its capacity to actively replicate in the presence of strong host CMV-specific immunity, may give CMV an advantage compared with other virus-based vaccine delivery platforms. In the present study, we tested the utility of mouse CMV (mCMV)-based vaccines expressing human prostate-specific antigen (PSA) for prostate cancer immunotherapy in double-transgenic mice expressing PSA and HLA-DRB1*1501 (DR2bxPSA F1 mice). We assessed the capacity of 2 mCMV-based vectors to induce PSA-specific CD8 T-cell responses and affect the growth of PSA-expressing Transgenic Adenocarcinoma of the Mouse Prostate tumors (TRAMP-PSA). In the absence of tumor challenge, immunization with mCMV vectors expressing either a H2-D(b)-restricted epitope PSA(65-73) (mCMV/PSA(65-73)) or the full-length gene for PSA (mCMV/PSA(FL)) induced comparable levels of CD8 T-cell responses that increased (inflated) with time. Upon challenge with TRAMP-PSA tumor cells, animals immunized with mCMV/PSA(65-73) had delay of tumor growth and increased PSA-specific CD8 T-cell responses, whereas animals immunized with mCMV/PSA(FL) showed progressive tumor growth and no increase in number of splenic PSA(65-73)-specific T cells. The data show that a prototype CMV-based prostate cancer vaccine can induce an effective antitumor immune response in a "humanized" double-transgenic mouse model. The observation that mCMV/PSA(FL) is not effective against TRAMP-PSA is consistent with our previous findings that HLA-DRB1*1501-restricted immune responses to PSA are associated with suppression of effective CD8 T-cell responses to TRAMP-PSA tumors.

  1. Combination of chondroitinase ABC, glial cell line-derived neurotrophic factor and Nogo A antibody delayed-release microspheres promotes the functional recovery of spinal cord injury.

    Science.gov (United States)

    Zhang, Yu; Gu, Zuchao; Qiu, Guixing; Song, Yueming

    2013-11-01

    Spinal cord injury (SCI) is one of the most devastating injuries for patients. Glial cell line-derived neurotrophic factor (GDNF) is an important neurotrophic factor for the regeneration of the spinal neuraxial bundle, but GDNF would degrade rapidly if the protein was injected into the site of injury; thus, it cannot exert its fullest effects. Therefore, we introduced a delivery system of GDNF, poly(lactide-co-glycolic acid) (PLGA) delayed-release microspheres, in the current study and observed the effect of PLGA-GDNF and the combination of PLGA-GDNF and another 2 agents PLGA-chondroitinase ABC (ChABC) and PLGA-Nogo A antibody in the treatment of SCI rats. Our results showed that PLGA-GDNF and the combination of chABC, GDNF, and Nogo A antibody microspheres could elevate the locomotor scores of SCI rats. The effect of PLGA-GDNF was much better than that of GDNF. The cortical somatosensory evoked potential was also improved by PLGA-GDNF and the combination of chABC, GDNF, and Nogo A antibody microspheres. Our results suggest that PLGA delayed-release microsphere may be a useful and effective tool in delivering protein agents into the injury sites of patients with SCI. This novel combination therapy may provide a new idea in promoting the functional recovery of the damaged spinal cord.

  2. Sickle Cell Disease (For Parents)

    Science.gov (United States)

    ... kidney damage, painful prolonged erections in males (priapism), eye damage, and delayed growth. previous continue Treatment Stem cell transplant (also called bone marrow transplant) is the only ...

  3. Delayed Recognition of Disorders of Sex Development (DSD: A Missed Opportunity for Early Diagnosis of Malignant Germ Cell Tumors

    Directory of Open Access Journals (Sweden)

    Remko Hersmus

    2012-01-01

    Full Text Available Disorders of sex development (DSD are defined as a congenital condition in which development of chromosomal, gonadal or anatomical sex is atypical. DSD patients with gonadal dysgenesis or hypovirilization, containing part of the Y chromosome (GBY, have an increased risk for malignant type II germ cell tumors (GCTs: seminomas and nonseminomas. DSD may be diagnosed in newborns (e.g., ambiguous genitalia, or later in life, even at or after puberty. Here we describe three independent male patients with a GCT; two were retrospectively recognized as DSD, based on the histological identification of both carcinoma in situ and gonadoblastoma in a single gonad as the cancer precursor. Hypospadias and cryptorchidism in their history are consistent with this conclusion. The power of recognition of these parameters is demonstrated by the third patient, in which the precursor lesion was diagnosed before progression to invasiveness. Early recognition based on these clinical parameters could have prevented development of (metastatic cancer, to be treated by systemic therapy. All three patients showed a normal male 46,XY karyotype, without obvious genetic rearrangements by high-resolution whole-genome copy number analysis. These cases demonstrate overlap between DSD and the so-called testicular dysgenesis syndrome (TDS, of significant relevance for identification of individuals at increased risk for development of a malignant GCT.

  4. Cell-free antigens from precocious Paracoccidioides brasiliensis culture induce a typical delayed-type hypersensitivity reaction

    Directory of Open Access Journals (Sweden)

    Fecchio CJ

    2011-01-01

    Full Text Available Cell-free antigens (CFAg derived from Paracoccidioides brasiliensis have typically been used in immunodiffusion reactions for serodiagnosis or therapeutic follow-up of paracoccidioidomycosis patients. Thus, we investigated the usefulness of CFAg obtained from cultures at different ages, to evaluate cellular immunity by the footpad test, in experimental murine paracoccidioidomycosis. Male mice infected with P. brasiliensis 265 strain were challenged in the footpad with CFAg obtained from four- (4d CFAg or 11-day-old cultures (11d CFAg. The increase in footpad swelling provoked by 4d CFAg and 11d CFAg was similar and showed significant difference in relation to control groups. However, the infiltrate pattern was strikingly different: 4d CFAg induced a predominant mononuclear infiltrate whereas 11d CFAg provoked a predominant polymophonuclear infiltrate. These different inflammatory patterns were associated with distinct electrophoretic characteristics. By comparison with 11d CFAg, 4d CFAg showed more numerous and intense bands, including a strong one of 43 kDa (gp43. These results suggest that CFAg derived from Pb 265 isolate can be used as a reagent to evaluate cellular immunity; however, the culture's age is critical because only young cultures are able to induce a typical mononuclear infiltrate. The efficacy of this new paracoccidioidin to assay the cellular immunity in infections caused by other P. brasiliensis isolates is under investigation.

  5. The combination of lanthanum chloride and the calcimimetic calindol delays the progression of vascular smooth muscle cells calcification

    Energy Technology Data Exchange (ETDEWEB)

    Ciceri, Paola; Volpi, Elisa; Brenna, Irene; Elli, Francesca [Renal Division and Laboratory of Experimental Nephrology, Dipartimento di Medicina e Chirurgia, Universita di Milano, Milan (Italy); Borghi, Elisa [Dipartimento di Salute Pubblica, Microbiologia e Virologia, Universita di Milano, Milan (Italy); Brancaccio, Diego [Renal Division and Laboratory of Experimental Nephrology, Dipartimento di Medicina e Chirurgia, Universita di Milano, Milan (Italy); Cozzolino, Mario, E-mail: mario.cozzolino@unimi.it [Renal Division and Laboratory of Experimental Nephrology, Dipartimento di Medicina e Chirurgia, Universita di Milano, Milan (Italy)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer Lanthanum reduces the progression of high phosphate-induced calcium deposition. Black-Right-Pointing-Pointer Calcium receptor agonists and the calcimimetic calindol reduce calcium deposition. Black-Right-Pointing-Pointer Lanthanum and calindol cooperate on reducing calcium deposition. Black-Right-Pointing-Pointer Lanthanum and calindol may interact with the same receptor. -- Abstract: Phosphate (Pi)-binders are commonly used in dialysis patients to control high Pi levels, that associated with vascular calcification (VC). The aim of this study was to investigate the effects of lanthanum chloride (LaCl{sub 3}) on the progression of high Pi-induced VC, in rat vascular smooth muscle cells (VSMCs). Pi-induced Ca deposition was inhibited by LaCl{sub 3}, with a maximal effect at 100 {mu}M (59.0 {+-} 2.5% inhibition). Furthermore, we studied the effects on VC of calcium sensing receptor (CaSR) agonists. Gadolinium chloride, neomycin, spermine, and the calcimimetic calindol significantly inhibited Pi-induced VC (55.9 {+-} 2.2%, 37.3 {+-} 4.7%, 30.2 {+-} 5.7%, and 63.8 {+-} 5.7%, respectively). To investigate the hypothesis that LaCl{sub 3} reduces the progression of VC by interacting with the CaSR, we performed a concentration-response curve of LaCl{sub 3} in presence of a sub-effective concentration of calindol (10 nM). Interestingly, this curve was shifted to the left (IC{sub 50} 9.6 {+-} 2.6 {mu}M), compared to the curve in the presence of LaCl{sub 3} alone (IC{sub 50} 19.0 {+-} 4.8 {mu}M). In conclusion, we demonstrated that lanthanum chloride effectively reduces the progression of high phosphate-induced vascular calcification. In addition, LaCl{sub 3} cooperates with the calcimimetic calindol in decreasing Ca deposition in this in vitro model. These results suggest the potential role of lanthanum in the treatment of VC induced by high Pi.

  6. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    Science.gov (United States)

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  7. Hydrogen sulfide delays GA-triggered programmed cell death in wheat aleurone layers by the modulation of glutathione homeostasis and heme oxygenase-1 expression.

    Science.gov (United States)

    Xie, Yanjie; Zhang, Chen; Lai, Diwen; Sun, Ya; Samma, Muhammad Kaleem; Zhang, Jing; Shen, Wenbiao

    2014-01-15

    Hydrogen sulfide (H2S) is considered as a cellular signaling intermediate in higher plants, but corresponding molecular mechanisms and signal transduction pathways in plant biology are still limited. In the present study, a combination of pharmacological and biochemical approaches was used to study the effect of H2S on the alleviation of GA-induced programmed cell death (PCD) in wheat aleurone cells. The results showed that in contrast with the responses of ABA, GA brought about a gradual decrease of l-cysteine desulfhydrase (LCD) activity and H2S production, and thereafter PCD occurred. Exogenous H2S donor sodium hydrosulfide (NaHS) not only effectively blocked the decrease of endogenous H2S release, but also alleviated GA-triggered PCD in wheat aleurone cells. These responses were sensitive to hypotaurine (HT), a H2S scavenger, suggesting that this effect of NaHS was in an H2S-dependent fashion. Further experiment confirmed that H2S, rather than other sodium- or sulphur-containing compounds derived from the decomposing of NaHS, was attributed to the rescuing response. Importantly, the reversing effect was associated with glutathione (GSH) because the NaHS triggered increases of endogenous GSH content and the ratio of GSH/oxidized GSH (GSSG) in GA-treated layers, and the NaHS-mediated alleviation of PCD was markedly eliminated by l-buthionine-sulfoximine (BSO, a selective inhibitor of GSH biosynthesis). The inducible effect of NaHS was also ascribed to the modulation of heme oxygenase-1 (HO-1), because the specific inhibitor of HO-1 zinc protoporphyrin IX (ZnPP) significantly suppressed the NaHS-related responses. By contrast, the above inhibitory effects were reversed partially when carbon monoxide (CO) aqueous solution or bilirubin (BR), two of the by-products of HO-1, was added, respectively. NaHS-triggered HO-1 gene expression in GA-treated layers was also confirmed. Together, the above results clearly suggested that the H2S-delayed PCD in GA-treated wheat

  8. (212)Pb-radioimmunotherapy induces G(2) cell-cycle arrest and delays DNA damage repair in tumor xenografts in a model for disseminated intraperitoneal disease.

    Science.gov (United States)

    Yong, Kwon Joong; Milenic, Diane E; Baidoo, Kwamena E; Brechbiel, Martin W

    2012-03-01

    In preclinical studies, targeted radioimmunotherapy using (212)Pb-TCMC-trastuzumab as an in vivo generator of the high-energy α-particle emitting radionuclide (212)Bi is proving an efficacious modality for the treatment of disseminated peritoneal cancers. To elucidate mechanisms associated with this therapy, mice bearing human colon cancer LS-174T intraperitoneal xenografts were treated with (212)Pb-TCMC-trastuzumab and compared with the nonspecific control (212)Pb-TCMC-HuIgG, unlabeled trastuzumab, and HuIgG, as well as untreated controls. (212)Pb-TCMC-trastuzumab treatment induced significantly more apoptosis and DNA double-strand breaks (DSB) at 24 hours. Rad51 protein expression was downregulated, indicating delayed DNA double-strand damage repair compared with (212)Pb-TCMC-HuIgG, the nonspecific control. (212)Pb-TCMC-trastuzumab treatment also caused G(2)-M arrest, depression of the S phase fraction, and depressed DNA synthesis that persisted beyond 120 hours. In contrast, the effects produced by (212)Pb-TCMC-HuIgG seemed to rebound by 120 hours. In addition, (212)Pb-TCMC-trastuzumab treatment delayed open chromatin structure and expression of p21 until 72 hours, suggesting a correlation between induction of p21 protein and modification in chromatin structure of p21 in response to (212)Pb-TCMC-trastuzumab treatment. Taken together, increased DNA DSBs, impaired DNA damage repair, persistent G(2)-M arrest, and chromatin remodeling were associated with (212)Pb-TCMC-trastuzumab treatment and may explain its increased cell killing efficacy in the LS-174T intraperitoneal xenograft model for disseminated intraperitoneal disease. PMID:22238365

  9. T Cells

    Science.gov (United States)

    T Cells - National Multiple Sclerosis Society Skip to navigation Skip to content Menu Navigation National Multiple Sclerosis Society Sign ... Is MS? Definition of MS T Cells T Cells Share Smaller Text Larger Text Print In this ...

  10. Cell counting.

    Science.gov (United States)

    Phelan, M C; Lawler, G

    2001-05-01

    This unit presents protocols for counting cells using either a hemacytometer or electronically using a Coulter counter. Cell counting with a hemacytometer permits effective discrimination of live from dead cells using trypan blue exclusion. In addition, the procedure is less subject to errors arising from cell clumping or size heterogeneity. Counting cells is more quickly and easily performed using an electronic counter, but live-dead discrimination is unreliable. Cell populations containing large numbers of dead cells and/or cell clumps are difficult to count accurately. In addition, electronic counting requires resetting of the instrument for cell populations of different sizes; heterogeneous populations can give rise to inaccurate counts, and resting and activated cells may require counting at separate settings. In general, electronic cell counting is best performed on fresh peripheral blood cells. PMID:18770655

  11. Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, E; Jørgensen, N; Brøndum-Nielsen, K;

    1998-01-01

    hypothesise that if the development of the testis is disturbed or delayed, primordial germ cells or gonocytes undergo maturation delay or differentiation arrest which may render them susceptible to neoplastic transformation. Morphologically homogenous premalignant carcinoma in situ (CIS) cells have...

  12. Heme Oxygenase-1 Delays Gibberellin-Induced Programmed Cell Death of Rice Aleurone Layers Subjected to Drought Stress by Interacting with Nitric Oxide.

    Science.gov (United States)

    Wu, Huangming; Zheng, Yan; Liu, Jing; Zhang, Heting; Chen, Huiping

    2015-01-01

    Cereal aleurone layers undergo a gibberellin (GA)-regulated process of programmed cell death (PCD) following germination. Heme oxygenase-1 (HO-1) is known as a rate-liming enzyme in the degradation of heme to biliverdin IXα, carbon monoxide (CO), and free iron ions (Fe(2+)). It is a critical component in plant development and adaptation to environment stresses. Our previous studies confirmed that HO-1 inducer hematin (Ht) promotes the germination of rice seeds in drought (20% polyethylene glycol-6000, PEG) conditions, but the corresponding effects of HO-1 on the alleviation of germination-triggered PCD in GA-treated rice aleurone layers remain unknown. The present study has determined that GA co-treated with PEG results in lower HO-1 transcript levels and HO activity, which in turn results in the development of vacuoles in aleurone cells, followed by PCD. The pharmacology approach illustrated that up- or down-regulated HO-1 gene expression and HO activity delayed or accelerated GA-induced PCD. Furthermore, the application of the HO-1 inducer Ht and nitric oxide (NO) donor sodium nitroprusside (SNP) not only activated HO-1 gene expression, HO activity, and endogenous NO content, but also blocked GA-induced rapid vacuolation and accelerated aleurone layers PCD under drought stress. However, both HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) and NO scavenger 2-(4-carboxyphenyl0-4, 4,5,5-tetramethylimidazoline-l-oxyl-3-oxide potassium salt (cPTIO) reserved the effects of Ht and SNP on rice aleurone layer PCD under drought stress by down-regulating endogenous HO-1 and NO, respectively. The inducible effects of Ht and SNP on HO-1 gene expression, HO activity, and NO content were blocked by cPTIO. Together, these results clearly suggest that HO-1 is involved in the alleviation of GA-induced PCD of drought-triggered rice aleurone layers by associating with NO. PMID:26834769

  13. Heme Oxygenase-1 Delays Gibberellin-Induced Programmed Cell Death of Rice Aleurone Layers Subjected to Drought Stress by Interacting with Nitric Oxide.

    Science.gov (United States)

    Wu, Huangming; Zheng, Yan; Liu, Jing; Zhang, Heting; Chen, Huiping

    2015-01-01

    Cereal aleurone layers undergo a gibberellin (GA)-regulated process of programmed cell death (PCD) following germination. Heme oxygenase-1 (HO-1) is known as a rate-liming enzyme in the degradation of heme to biliverdin IXα, carbon monoxide (CO), and free iron ions (Fe(2+)). It is a critical component in plant development and adaptation to environment stresses. Our previous studies confirmed that HO-1 inducer hematin (Ht) promotes the germination of rice seeds in drought (20% polyethylene glycol-6000, PEG) conditions, but the corresponding effects of HO-1 on the alleviation of germination-triggered PCD in GA-treated rice aleurone layers remain unknown. The present study has determined that GA co-treated with PEG results in lower HO-1 transcript levels and HO activity, which in turn results in the development of vacuoles in aleurone cells, followed by PCD. The pharmacology approach illustrated that up- or down-regulated HO-1 gene expression and HO activity delayed or accelerated GA-induced PCD. Furthermore, the application of the HO-1 inducer Ht and nitric oxide (NO) donor sodium nitroprusside (SNP) not only activated HO-1 gene expression, HO activity, and endogenous NO content, but also blocked GA-induced rapid vacuolation and accelerated aleurone layers PCD under drought stress. However, both HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) and NO scavenger 2-(4-carboxyphenyl0-4, 4,5,5-tetramethylimidazoline-l-oxyl-3-oxide potassium salt (cPTIO) reserved the effects of Ht and SNP on rice aleurone layer PCD under drought stress by down-regulating endogenous HO-1 and NO, respectively. The inducible effects of Ht and SNP on HO-1 gene expression, HO activity, and NO content were blocked by cPTIO. Together, these results clearly suggest that HO-1 is involved in the alleviation of GA-induced PCD of drought-triggered rice aleurone layers by associating with NO.

  14. Heme oxygenase-1 delays gibberellin-induced programmed cell death of rice aleurone layers subjected to drought stress by interacting with nitric oxide

    Directory of Open Access Journals (Sweden)

    Huangming eWu

    2016-01-01

    Full Text Available Cereal aleurone layers undergo a gibberellin (GA-regulated process of programmed cell death (PCD following germination. Heme oxygenase-1 (HO-1 is known as a rate-liming enzyme in the degradation of heme to biliverdin IXα (BV, carbon monoxide (CO, and free iron ions (Fe2+. It is a critical component in plant development and adaptation to environment stresses. Our previous studies confirmed that HO-1 inducer hematin (Ht promotes the germination of rice seeds in drought (20% polyethylene glycol-6000, PEG conditions, but the corresponding effects of HO-1 on the alleviation of germination-triggered PCD in GA-treated rice aleurone layers remain unknown. The present study has determined that GA co-treated with PEG results in lower HO-1 transcript levels and HO activity, which in turn results in the development of vacuoles in aleurone cells, followed by PCD. The pharmacology approach illustrated that up- or down-regulated HO-1 gene expression and HO activity delayed or accelerated GA-induced PCD. Furthermore, the application of the HO-1 inducer hematin and nitric oxide (NO donor sodium nitroprusside (SNP not only activated HO-1 gene expression, HO activity, and endogenous NO content, but also blocked GA-induced rapid vacuolation and accelerated aleurone layers PCD under drought stress. However, both HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX and NO scavenger 2-(4-carboxyphenyl0-4, 4, 5, 5-tetramethylimidazoline-l-oxyl-3-oxide potassium salt (cPTIO reserved the effects of hematin and SNP on rice aleurone layer PCD under drought stress by down-regulating endogenous HO-1 and NO, respectively. The inducible effects of hematin and SNP on HO-1 gene expression, HO activity, and NO content were blocked by cPTIO. Together, these results clearly suggest that HO-1 is involved in the alleviation of GA-induced PCD of drought-triggered rice aleurone layers by associating with NO.

  15. Toxin coupled MHC class I tetramers can specifically ablate autoreactive CD8+ T cells and delay diabetes in NOD mice1

    OpenAIRE

    Vincent, Benjamin G.; Young, Ellen F.; Buntzman, Adam S.; Stevens, Rosemary; Kepler, Thomas B.; Tisch, Roland; Frelinger, Jeffrey A.; Hess, Paul R.

    2010-01-01

    There is compelling evidence that self reactive CD8+ T cells are a major factor in development and progression of Type 1 diabetes in animals and humans. Hence, great effort has been expended to define the specificity of autoimmune CD8+ T cells, and to alter their responses. Much work has focused on tolerization of T cells using proteins or peptides. A weakness in this approach is residual autoreactive T cells may be activated and exacerbate disease.

  16. Cell cycle delay in murine pre-osteoblasts is more pronounced after exposure to high-LET compared to low-LET radiation.

    Science.gov (United States)

    Hu, Yueyuan; Hellweg, Christine E; Baumstark-Khan, Christa; Reitz, Günther; Lau, Patrick

    2014-03-01

    Space radiation contains a complex mixture of particles comprised primarily of protons and high-energy heavy ions. Radiation risk is considered one of the major health risks for astronauts who embark on both orbital and interplanetary space missions. Ionizing radiation dose-dependently kills cells, damages genetic material, and disturbs cell differentiation and function. The immediate response to ionizing radiation-induced DNA damage is stimulation of DNA repair machinery and activation of cell cycle regulatory checkpoints. To date, little is known about cell cycle regulation after exposure to space-relevant radiation, especially regarding bone-forming osteoblasts. Here, we assessed cell cycle regulation in the osteoblastic cell line OCT-1 after exposure to various types of space-relevant radiation. The relative biological effectiveness (RBE) of ionizing radiation was investigated regarding the biological endpoint of cellular survival ability. Cell cycle progression was examined following radiation exposure resulting in different RBE values calculated for a cellular survival level of 1 %. Our findings indicate that radiation with a linear energy transfer (LET) of 150 keV/μm was most effective in inducing reproductive cell killing by causing cell cycle arrest. Expression analyses indicated that cells exposed to ionizing radiation exhibited significantly up-regulated p21(CDKN1A) gene expression. In conclusion, our findings suggest that cell cycle regulation is more sensitive to high-LET radiation than cell survival, which is not solely regulated through elevated CDKN1A expression. PMID:24240273

  17. Galvanic Cells

    Science.gov (United States)

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  18. Cell Biochips

    Science.gov (United States)

    Pioufle, B. Le; Picollet-D'Hahan, N.

    A cell biochip is a microsystem, equipped with electronic and microfluidic functions, designed to manipulate or analyse living cells. The first publications in this emerging area of research appeared toward the end of the 1980s. In 1989 Washizu described a biochip designed to fuse two cells by electropermeabilisation of the cytoplasmic membrane [1]. Research centers have devised a whole range of cell chip structures, for simultaneous or sequential analysis of single cells, cell groups, or cell tissues reconstituted on the chip. The cells are arranged in a square array on a parallel cell chip for parallel analysis, while they are examined and processed one by one in a microchannel in the case of a series cell chip. In contrast to these biochips for high-throughput analysis of a large number of cells, single-cell chips focus on the analysis of a single isolated cell. As in DNA microarrays, where a large number of oligonucleotides are ordered in a matrix array, parallel cell chips order living cells in a similar way. At each point of the array, the cells can be isolated, provided that the cell type allows this, e.g., blood cells, or cultivated in groups (most adhesion cells can only survive in groups). The aim is to allow massively parallel analysis or processing. Le Pioufle et al. describe a microdevice for the culture of single cells or small groups of cells in a micropit array [2]. Each pit is equipped to stimulate the cell or group of cells either electrically or fluidically. Among the applications envisaged are gene transfer, cell sorting, and screening in pharmacology. A complementary approach, combining the DNA microarray and cell biochip ideas, has been put forward by Bailey et al. [3]. Genes previously arrayed on the chip transfect the cultured cells on the substrate depending on their position in the array (see Fig. 19.1). This way of achieving differential lipofection on a chip was then taken up again by Yoshikawa et al. [4] with primary cells, more

  19. Cell Wall

    OpenAIRE

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Albenne, Cécile; Pont-Lezica, Rafael F

    2008-01-01

    This chapter covers our present knowledge of cell wall proteomics highlighting the distinctive features of cell walls and cell wall proteins in relation to problems encountered for protein extraction, separation and identification. It provides clues to design strategies for efficient cell wall proteomic studies. It gives an overview of the kinds of proteins that have yet been identified: the expected proteins vs the identified proteins. Finally, the new vision of the cell wall proteome, and t...

  20. Stem Cells

    OpenAIRE

    Madhukar Thakur

    2009-01-01

    Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in ...

  1. Delay of HeLa cell cleavage into interphase using dihydrocytochalasin B: retention of a postmitotic spindle and telophase disc correlates with synchronous cleavage recovery

    OpenAIRE

    1995-01-01

    The molecular signals that determine the position and timing of the cleavage furrow during mammalian cell cytokinesis are presently unknown. We have studied in detail the effect of dihydrocytochalasin B (DCB), a drug that interferes with actin assembly, on specific late mitotic events in synchronous HeLa cells. When cleavage furrow formation is blocked at 10 microM DCB, cells return to interphase by the criteria of reformation of nuclei with lamin borders, degradation of the cyclin B componen...

  2. Optimization of cell-wall skeleton derived from Mycobacterium bovis BCG Tokyo 172 (SMP-105) emulsion in delayed-type hypersensitivity and antitumor models.

    Science.gov (United States)

    Miyauchi, M; Murata, M; Fukushima, A; Sato, T; Nakagawa, M; Fujii, T; Koseki, N; Chiba, N; Kashiwazaki, Y

    2012-08-01

    Cell-wall skeleton prepared from Mycobacterium bovis BCG (BCG-CWS) is known as a potent adjuvant and has been shown to possess antitumor activity in many non-clinical and clinical studies. As there are no approved BCG-CWS formulations for cancer therapy, we investigated the potential for cancer immunotherapy of SMP-105, our originally produced BCG-CWS. For optimizing SMP-105 emulsion, we compared the effects of drakeoland squalane-based SMP-105 emulsions on IFN-γ production in rats and evaluated their ability to induce skin reaction in guinea pigs. Both emulsions had the same activity in both experiments. We selected squalane as base material and produced two types of squalane-based formulations (vialed emulsion and pumped emulsion) that can easily be prepared as oil-in-water emulsions. Although the vialed emulsion showed the same pattern of distribution as a usual homogenized emulsion, the pumped emulsion showed more uniform distribution than the other two emulsions. Whereas both emulsions enhanced strong delayed type hypersensitivity (DTH) reaction in a mouse model, the pumped emulsion induced slightly smaller edema. Data on oil droplet size distribution suggest that few micrometer oil droplet size might be appropriate for oil-in-water microemulsion of SMP-105. The antitumor potency of SMP-105 emulsion was stronger than that of some of the launched toll-like receptor (TLR) agonists (Aldara cream, Picibanil, and Immunobladder). Aldara and Picibanil showed limited antitumor effectiveness, while Immunobladder had almost the same effect as SMP-105 at the highest dose, but needed about 10 times the amount of SMP-105. These findings first indicate that SMP-105 has great potential in cancer immunotherapy.

  3. Minocycline protects retinal ganglion cells after optic nerve crush injury in mice by delaying autophagy and upregulating nuclear factor-κB2

    Institute of Scientific and Technical Information of China (English)

    Jiao Xiaoling; Peng Yuan; Yang Liu

    2014-01-01

    Background Currently,no medicine is available that can prevent or treat neural damage associated with optic nerve injury.Minocycline is recently reported to have a neuroprotective function.The aims of this study were to exarmine the neuroprotective effect of minocycline on retinal ganglion cells (RGCs) and determine its underlying mechanisms,using a mouse model of optic nerve crush (ONC).Methods ONC was performed in the left eye of adult male mice,and the mice were randomly divided into minocycline-treated group and saline-treated control group.The mice without receiving ONC injury were used as positive controls.RGC densities were assessed in retinal whole mounts with immunofluorescence labeling of βⅢ-tubulin.Transmission electron microscopy was used to detect RGC morphologies,and Western blotting and real-time PCR were applied to investigate the expression of autophagy markers LC3-Ⅰ,LC3-Ⅱ,and transcriptional factors nuclear factor-κB1 (NF-κB1),NF-κB2.Results In the early stage after ONC (at Days 4 and 7),the density of RGCs in the minocycline-treated group was higher than that of the saline-treated group.Electron micrographs showed that minocycline prevented nuclei and mitochondria injuries at Day 4.Western blotting analysis demonstrated that the conversion of LC3-Ⅰ to LC3-Ⅱ was reduced in the minocycline-treated group at Days 4 and 7,which meant autophagy process was inhibited by minocycline.In addition,the gene expression of NF-κB2 was upregulated by minocycline at Day 4.Conclusion The neuroprotective effect of minocycline is generated in the early stage after ONC in mice,partly through delaying autophagy process and regulating NF-κB2 pathway.

  4. Two phenotypically distinct T cells are involved in ultraviolet-irradiated urocanic acid-induced suppression of the efferent delayed-type hypersensitivity response to herpes simplex virus, type 1 in vivo

    International Nuclear Information System (INIS)

    When UVB-irradiated urocanic acid, the putative photoreceptor/mediator for UVB suppression, is administered to mice it induces a dose-dependent suppression of the delayed-type hypersensitivity response to herpes simplex virus, type 1 (HSV-1), of similar magnitude to that induced by UV irradiation of mice. In this study, the efferent suppression of delayed-type hypersensitivity by UV-irradiated urocanic acid is demonstrated to be due to 2 phenotypically distinct T cells, (Thy1+, L3T4-, Ly2+) and (Thy1+, L3T4+, Ly2-). The suppression is specific for HSV-1. This situation parallels the generation of 2 distinct T-suppressor cells for HSV-1 by UV irradiation of mice and provides further evidence for the involvement of urocanic acid in the generation of UVB suppression

  5. Engineering cell-cell signaling.

    Science.gov (United States)

    Blagovic, Katarina; Gong, Emily S; Milano, Daniel F; Natividad, Robert J; Asthagiri, Anand R

    2013-10-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling on the basis of quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilize synthetic cells, advanced 'chassis' and predictive modeling to engineer the form and function of living tissues.

  6. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

    Cell motility is a fascinating example of cell behavior which is fundamentally important to a number of biological and pathological processes. It is based on a complex self-organized mechano-chemical machine consisting of cytoskeletal filaments and molecular motors. In general, the cytoskeleton is responsible for the movement of the entire cell and for movements within the cell. The main challenge in the field of cell motility is to develop a complete physical description on how and why cells move. For this purpose new ways of modeling the properties of biological cells have to be found. This long term goal can only be achieved if new experimental techniques are developed to extract physical information from these living systems and if theoretical models are found which bridge the gap between molecular and mesoscopic length scales. Cell Motility gives an authoritative overview of the fundamental biological facts, theoretical models, and current experimental developments in this fascinating area.

  7. Photovoltaic Cells

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2012-04-01

    Full Text Available The article deals with an overview of photovoltaic cells that are currently manufactured and those being developed, including one or several p-n junction, organic and dye-sensitized cells using quantum dots. The paper describes the advantages and disadvantages of various photovoltaic cells, identifies the main parameters, explains the main reasons for the losses that may occur in photovoltaic cells and looks at the ways to minimize them.Article in Lithuanian

  8. Solar cells

    Science.gov (United States)

    Cuquel, A.; Roussel, M.

    The physical and electronic characteristics of solar cells are discussed in terms of space applications. The principles underlying the photovoltaic effect are reviewed, including an analytic model for predicting the performance of individual cells and arrays of cells. Attention is given to the effects of electromagnetic and ionizing radiation, micrometeors, thermal and mechanical stresses, pollution and degassing encountered in space. The responses of different types of solar cells to the various performance-degrading agents are examined, with emphasis on techniques for quality assurance in the manufacture and mounting of Si cells.

  9. Engineering Cell-Cell Signaling

    OpenAIRE

    Blagovic, Katarina; Gong, Emily S.; Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R

    2013-01-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cel...

  10. Antigenicity and immunogenicity of an extract from the cell wall and cell membrane of Histoplasma capsulatum yeast cells.

    OpenAIRE

    Gómez, A M; Rhodes, J C; Deepe, G S

    1991-01-01

    In order to identify T-cell antigens from Histoplasma capsulatum yeast cells, we prepared a detergent extract of the cell wall and cell membrane of yeast-phase H. capsulatum G217B and analyzed its antigenicity and immunogenicity. Mice injected with viable H. capsulatum yeast cells or with 500 or 1,000 micrograms of the extract mounted a delayed-type hypersensitivity response to solubilized cell wall and cell membrane. Vaccination with this antigenic preparation conferred a protective immune r...

  11. Delayed cell cycle progression in selenoprotein W depleted cells is regulated by a mitogen-activated protein kinase kinase 4–p38–p53 pathway

    Science.gov (United States)

    Selenoprotein W (SEPW1) is a ubiquitous, highly conserved thioredoxin-like protein whose depletion causes a p53- and p21Cip1-dependent G1-phase cell cycle arrest in breast and prostate epithelial cells. SEPW1 depletion increases phosphorylation of Ser33 in p53, which is associated with decreased p53...

  12. Mutation of EMG1 causing Bowen-Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay.

    Science.gov (United States)

    Armistead, Joy; Hemming, Richard; Patel, Nehal; Triggs-Raine, Barbara

    2014-06-01

    Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1). EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  13. Mutation of EMG1 causing Bowen–Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay

    Directory of Open Access Journals (Sweden)

    Joy Armistead

    2014-06-01

    Full Text Available Bowen–Conradi syndrome (BCS is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1. EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  14. Targeted cytosine deaminase-uracil phosphoribosyl transferase suicide gene therapy induces small cell lung cancer-specific cytotoxicity and tumor growth delay

    DEFF Research Database (Denmark)

    Christensen, Camilla L; Gjetting, Torben; Poulsen, Thomas Tuxen;

    2010-01-01

    Small cell lung cancer (SCLC) is a highly malignant cancer for which there is no curable treatment. Novel therapies are therefore in great demand. In the present study we investigated the therapeutic effect of transcriptionally targeted suicide gene therapy for SCLC based on the yeast cytosine de......). Therapeutic effect was evaluated in vitro in SCLC cell lines and in vivo in SCLC xenografted nude mice using the nonviral nanoparticle DOTAP/cholesterol for transgene delivery....

  15. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  16. Leydig cell tumours in childhood.

    Science.gov (United States)

    Mengel, W; Knorr, D

    1983-01-01

    Two cases of Leydig cell tumours in childhood are presented. In one case, delayed diagnosis and operation led to pubertas praecox vera whereas in the other case normal growth and development occurred after early diagnosis and operation. PMID:6878724

  17. Types of Stem Cells

    Science.gov (United States)

    ... PDF) Download an introduction to stem cells and stem cell research. Stem Cell Glossary Stem cell terms to know. ... stem cells blog from the International Society for Stem Cell Research. Learn About Stem Cells From Lab to You ...

  18. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  19. Cell suicide

    International Nuclear Information System (INIS)

    In the fight of the cell against the damages caused to its DNA by genotoxic agents and specially by ionizing radiations, the p53 protein plays a central part. It intervenes in the proliferation control and the differentiation but also in the keeping of genome integrity. It can direct the damages cells toward suicide, or apoptosis, to avoid the risk of tumor appearance that would be fatal to the whole organism. That is by the disordered state of cells suicide programs that the tumor cells are going to develop. The knowledge of apoptosis mechanisms, to eventually start them on demand, rises up broad hopes in the cancer therapy. (N.C.)

  20. Time-Delay HIV-1 Virus Dynamics Model with Both Virus-to-Cell Infection and Cell-to-Cell Transmission and Cure Rate%带有治愈率的病毒感染细胞与细胞感染细胞的HIV-1时滞病毒动力学模型

    Institute of Scientific and Technical Information of China (English)

    管宪伟; 徐瑞

    2016-01-01

    In this paper,a mathematical model incorporating cell-to-cell transmission and virus-to-cell infection with cure rate and time delay is investigated.Through calculation and analysis, the explicit expression of the basic reproduction number of this model is obtained.It is proven that the infection-free equilibrium is globally asymptotically stable if the basic reproduction number is less than one,and the model is permanent if the basic reproduction number is greater than one.%研究了一类具有治愈率和时滞的HIV-1(获得性免疫缺陷病)病毒动力学模型的性质,在模型中同时考虑了病毒感染细胞和细胞感染细胞的感染机制.通过计算和分析,得到了基本再生数的显式表达式,并且得到当基本再生数小于1时,无病平衡点全局渐近稳定,当基本再生数大于1时,病毒在宿主体内是持续生存的.

  1. Potential Linkage of Satellite Cells and Delayed Onset Muscle Soreness%肌卫星细胞与延迟性肌肉酸痛的潜在联系

    Institute of Scientific and Technical Information of China (English)

    赵新娟; 杜海平; 王植元; 张翔

    2015-01-01

    By reviewing related literatures retrieved through the CNKI and Pubmed database. the continuous intensive eccentric exercise may have certain regulation to skeletal muscle satellite cell growth factor which is closely related to repair skeletal muscle damage ; delayed onset muscle soreness sequential timing has certain correlation with skeletal muscle satellite cell proliferation; delayed ache of skeletal muscle special micro environment certain extent to stimulate the secretion of skeletal muscle satellite cell growth factor and promote skeletal muscle sarcomere remodeling.%检索中国知网和Pubmed数据库中相关文献并对其进行综述。持续大强度离心运动可能对与骨骼肌损伤修复密切相关的骨骼肌卫星细胞生长因子具有一定的调节作用;持续大强度离心运动引发的延迟性肌肉酸痛的发生时序与骨骼肌卫星细胞增殖时序存在一定的相关性;延迟性酸痛的骨骼肌特殊微环境一定程度上刺激骨骼肌卫星细胞生长因子的分泌,促进骨骼肌肌节重塑。

  2. Radiosensitivity of mesothelioma cell lines

    International Nuclear Information System (INIS)

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters α and β of the linear quadratic model (LQ-model) and mean inactivation dose (DMID) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean α value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The α/β ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.)

  3. Retinoid- and sodium-butyrate– induced decrease in heat shock protein 70 membrane-positive tumor cells is associated with reduced sensitivity to natural killer cell lysis, growth delay, and altered growth morphology

    OpenAIRE

    Gehrmann, Mathias; Schönberger, Johann; Zilch, Tanja; Rossbacher, Lydia; Thonigs, Gerald; Eilles, Christoph; Multhoff, Gabriele

    2005-01-01

    Human tumors frequently present heat shock protein 70 (Hsp70) on their cell membranes, whereas corresponding normal tissues fail to do so. Therefore, an Hsp70 membrane-positive phenotype provided a tumor-specific marker. Moreover, membrane-bound Hsp70 provides a target structure for the cytolytic attack mediated by natural killer (NK) cells. Vitamin A derivatives 13-cis retinoic acid (13-RA) and all-trans retinoic acid (ATRA) and sodium-butyrate (SBU) are known for their redifferentiating cap...

  4. Reprogrammed Pluripotent Stem Cells from Somatic Cells

    OpenAIRE

    Kim, Jong Soo; Choi, Hyun Woo; Choi, Sol; Do, Jeong Tae

    2011-01-01

    Pluripotent stem cells, such as embryonic stem (ES) cells, can differentiate into all cell types. So, these cells can be a biological resource for regenerative medicine. However, ES cells known as standard pluripotent cells have problem to be used for cell therapy because of ethical issue of the origin and immune response on the graft. Hence, recently reprogrammed pluripotent cells have been suggested as an alternative source for regenerative medicine. Somatic cells can acquire the ES cell-li...

  5. Delayed translational silencing of ceruloplasmin transcript in gamma interferon-activated U937 monocytic cells: role of the 3' untranslated region

    Science.gov (United States)

    Mazumder, B.; Fox, P. L.

    1999-01-01

    Ceruloplasmin (Cp) is an acute-phase protein with ferroxidase, amine oxidase, and pro- and antioxidant activities. The primary site of Cp synthesis in human adults is the liver, but it is also synthesized by cells of monocytic origin. We have shown that gamma interferon (IFN-gamma) induces the synthesis of Cp mRNA and protein in monocytic cells. We now report that the induced synthesis of Cp is terminated by a mechanism involving transcript-specific translational repression. Cp protein synthesis in U937 cells ceased after 16 h even in the presence of abundant Cp mRNA. RNA isolated from cells treated with IFN-gamma for 24 h exhibited a high in vitro translation rate, suggesting that the transcript was not defective. Ribosomal association of Cp mRNA was examined by sucrose centrifugation. When Cp synthesis was high, i.e., after 8 h of IFN-gamma treatment, Cp mRNA was primarily associated with polyribosomes. However, after 24 h, when Cp synthesis was low, Cp mRNA was primarily in the nonpolyribosomal fraction. Cytosolic extracts from cells treated with IFN-gamma for 24 h, but not for 8 h, contained a factor which blocked in vitro Cp translation. Inhibitor expression was cell type specific and present in extracts of human cells of myeloid origin, but not in several nonmyeloid cells. The inhibitory factor bound to the 3' untranslated region (3'-UTR) of Cp mRNA, as shown by restoration of in vitro translation by synthetic 3'-UTR added as a "decoy" and detection of a binding complex by RNA gel shift analysis. Deletion mapping of the Cp 3'-UTR indicated an internal 100-nucleotide region of the Cp 3'-UTR that was required for complex formation as well as for silencing of translation. Although transcript-specific translational control is common during development and differentiation and global translational control occurs during responses to cytokines and stress, to our knowledge, this is the first report of translational silencing of a specific transcript following cytokine

  6. PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53

    DEFF Research Database (Denmark)

    Zandi, Roza; Selivanova, Galina; Christensen, Camilla Laulund;

    2011-01-01

    Small cell lung cancer (SCLC) is a highly malignant disease with poor prognosis, necessitating the need to develop new and efficient treatment modalities. PRIMA-1(Met) (p53-dependent reactivation of massive apoptosis), also known as APR-246, is a small molecule, which restores tumor suppressor...... function to mutant p53 and induces cancer cell death in various cancer types. Since p53 is mutated in more than 90% of SCLC, we investigated the ability of PRIMA-1(Met) to induce apoptosis and inhibit tumor growth in SCLC with different p53 mutations....

  7. Fuel Cells

    Science.gov (United States)

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  8. Targeted cytosine deaminase-uracil phosphoribosyl transferase suicide gene therapy induces small cell lung cancer-specific cytotoxicity and tumor growth delay

    DEFF Research Database (Denmark)

    Christensen, Camilla L; Gjetting, Torben; Poulsen, Thomas Tuxen;

    2010-01-01

    Small cell lung cancer (SCLC) is a highly malignant cancer for which there is no curable treatment. Novel therapies are therefore in great demand. In the present study we investigated the therapeutic effect of transcriptionally targeted suicide gene therapy for SCLC based on the yeast cytosine...

  9. HIV-Exposed Uninfected Infants Show Robust Memory B-Cell Responses in Spite of a Delayed Accumulation of Memory B Cells: an Observational Study in the First 2 Years of Life.

    Science.gov (United States)

    Nduati, Eunice W; Nkumama, Irene N; Gambo, Faith K; Muema, Daniel M; Knight, Miguel G; Hassan, Amin S; Jahangir, Margaret N; Etyang, Timothy J; Berkley, James A; Urban, Britta C

    2016-07-01

    Improved HIV care has led to an increase in the number of HIV-exposed uninfected (HEU) infants born to HIV-infected women. Although they are uninfected, these infants experience increased morbidity and mortality. One explanation may be that their developing immune system is altered by HIV exposure, predisposing them to increased postnatal infections. We explored the impact of HIV exposure on the B-cell compartment by determining the B-cell subset distribution, the frequency of common vaccine antigen-specific memory B cells (MBCs), and the levels of antibodies to the respective antigens in HEU and HIV-unexposed uninfected (HUU) infants born to uninfected mothers, using flow cytometry, a B-cell enzyme-linked immunosorbent spot assay, and an enzyme-linked immunosorbent assay, respectively, during the first 2 years of life. For the majority of the B-cell subsets, there were no differences between HEU and HUU infants. However, HIV exposure was associated with a lower proportion of B cells in general and MBCs in particular, largely due to a lower proportion of unswitched memory B cells. This reduction was maintained even after correcting for age. These phenotypic differences in the MBC compartment did not affect the ability of HEU infants to generate recall responses to previously encountered antigens or reduce the antigen-specific antibody levels at 18 months of life. Although HIV exposure was associated with a transient reduction in the proportion of MBCs, we found that the ability of HEU infants to mount robust MBC and serological responses was unaffected. PMID:27170641

  10. CASE REPORT OF LANGERHANS CELL HISTIOCYTOSIS

    OpenAIRE

    Umesh Reddy; Somaiah; Ravikanth; Navneeth Reddy; Gowthami

    2014-01-01

    : Langerhans cell histiocytosis (LCH) is a rare proliferative disorder in which pathological Langerhans cells (LCs) accumulate in a variety of organs. This report describes a boy with Langerhans' cell histiocytosis who presented with primarily soft tissue swellings, without pain. A high index of suspicion is required to reach to a diagnosis of langerhans cell histiocytosis to prevent delay in proper management of this disease.

  11. ALMS1-deficient fibroblasts over-express extra-cellular matrix components, display cell cycle delay and are resistant to apoptosis.

    Directory of Open Access Journals (Sweden)

    Elisabetta Zulato

    Full Text Available Alström Syndrome (ALMS is a rare genetic disorder (483 living cases, characterized by many clinical manifestations, including blindness, obesity, type 2 diabetes and cardiomyopathy. ALMS is caused by mutations in the ALMS1 gene, encoding for a large protein with implicated roles in ciliary function, cellular quiescence and intracellular transport. Patients with ALMS have extensive fibrosis in nearly all tissues resulting in a progressive organ failure which is often the ultimate cause of death. To focus on the role of ALMS1 mutations in the generation and maintenance of this pathological fibrosis, we performed gene expression analysis, ultrastructural characterization and functional assays in 4 dermal fibroblast cultures from ALMS patients. Using a genome-wide gene expression analysis we found alterations in genes belonging to specific categories (cell cycle, extracellular matrix (ECM and fibrosis, cellular architecture/motility and apoptosis. ALMS fibroblasts display cytoskeleton abnormalities and migration impairment, up-regulate the expression and production of collagens and despite the increase in the cell cycle length are more resistant to apoptosis. Therefore ALMS1-deficient fibroblasts showed a constitutively activated myofibroblast phenotype even if they do not derive from a fibrotic lesion. Our results support a genetic basis for the fibrosis observed in ALMS and show that both an excessive ECM production and a failure to eliminate myofibroblasts are key mechanisms. Furthermore, our findings suggest new roles for ALMS1 in both intra- and extra-cellular events which are essential not only for the normal cellular function but also for cell-cell and ECM-cell interactions.

  12. Sexuality and sickle cell anemia

    OpenAIRE

    Viviane de Almeida Côbo; Cibele Alves Chapadeiro; João Batista Ribeiro; Helio Moraes-Souza; Paulo Roberto Juliano Martins

    2013-01-01

    BACKGROUND: Sickle cell disease, the most common hereditary blood disease in the world, is the result of an atypical hemoglobin called S (Hb S) which, when homozygous (Hb SS) is the cause of sickle cell anemia. Changes of puberty, correlated with a delayed growth spurt, begin late in both male and female sickle cell anemia individuals with repercussions on sexuality and reproduction. The objectives of this exploratory and descriptive study were to characterize the development of sexuality in ...

  13. Ex vivo expanded human regulatory T cells delay islet allograft rejection via inhibiting islet-derived monocyte chemoattractant protein-1 production in CD34+ stem cells-reconstituted NOD-scid IL2rγnull mice.

    Directory of Open Access Journals (Sweden)

    Fang Xiao

    Full Text Available Type 1 diabetes mellitus (T1DM is an autoimmune disease caused by immune-mediated destruction of insulin-secreting β cells of the pancreas. Near complete dependence on exogenous insulin makes T1DM very difficult to control, with the result that patients are exposed to high blood glucose and risk of diabetic complications and/or intermittent low blood glucose that can cause unconsciousness, fits and even death. Allograft transplantation of pancreatic islets restores normoglycemia with a low risk of surgical complications. However, although successful immediately after transplantation, islets are progressively lost, with most of the patients requiring exogenous insulin within 2 years post-transplant. Therefore, there is an urgent requirement for the development of new strategies to prevent islet rejection. In this study, we explored the importance of human regulatory T cells in the control of islets allograft rejection. We developed a pre-clinical model of human islet transplantation by reconstituting NOD-scid IL2rγnull mice with cord blood-derived human CD34+ stem cells and demonstrated that although the engrafted human immune system mediated the rejection of human islets, their survival was significantly prolonged following adoptive transfer of ex vivo expanded human Tregs. Mechanistically, Tregs inhibited the infiltration of innate immune cells and CD4+ T cells into the graft by down-regulating the islet graft-derived monocyte chemoattractant protein-1. Our findings might contribute to the development of clinical strategies for Treg therapy to control human islet rejection. We also show for the first time that CD34+ cells-reconstituted NOD-scid IL2rγnull mouse model could be beneficial for investigating human innate immunity in vivo.

  14. Foxp3⁺ regulatory T cells delay expulsion of intestinal nematodes by suppression of IL-9-driven mast cell activation in BALB/c but not in C57BL/6 mice.

    Directory of Open Access Journals (Sweden)

    Birte Blankenhaus

    2014-02-01

    Full Text Available Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3⁺ regulatory T cells (Treg in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3⁺ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in

  15. Foxp3+ Regulatory T Cells Delay Expulsion of Intestinal Nematodes by Suppression of IL-9-Driven Mast Cell Activation in BALB/c but Not in C57BL/6 Mice

    Science.gov (United States)

    Brenz, Yannick; Eschbach, Marie-Luise; Hartmann, Wiebke; Haben, Irma; Sparwasser, Tim; Huehn, Jochen; Kühl, Anja; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Breloer, Minka

    2014-01-01

    Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3+ regulatory T cells (Treg) in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre) BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3+ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in Treg-depleted C57BL/6

  16. Foxp3⁺ regulatory T cells delay expulsion of intestinal nematodes by suppression of IL-9-driven mast cell activation in BALB/c but not in C57BL/6 mice.

    Science.gov (United States)

    Blankenhaus, Birte; Reitz, Martina; Brenz, Yannick; Eschbach, Marie-Luise; Hartmann, Wiebke; Haben, Irma; Sparwasser, Tim; Huehn, Jochen; Kühl, Anja; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Breloer, Minka

    2014-02-01

    Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3⁺ regulatory T cells (Treg) in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre) BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3⁺ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in Treg-depleted C57BL/6

  17. [Cell cultures].

    Science.gov (United States)

    Cipro, Simon; Groh, Tomáš

    2014-01-01

    Cell or tissue cultures (both terms are interchangeable) represent a complex process by which eukaryotic cells are maintained in vitro outside their natural environment. They have a broad usage covering not only scientific field but also diagnostic one since they represent the most important way of monoclonal antibodies production which are used for both diagnostic and therapeutic purposes. Cell cultures are also used as a "cultivation medium" in virology and for establishing proliferating cells in cytodiagnostics. They are well-established and easy-to-handle models in the area of research, e.g. as a precious source of nucleic acids or proteins. This paper briefly summarizes their importance and methods as well as the pitfalls of the cultivation and new trends in this field. PMID:24624984

  18. Fuel cells

    Directory of Open Access Journals (Sweden)

    D. N. Srivastava

    1962-05-01

    Full Text Available The current state of development of fuel cells as potential power sources is reviewed. Applications in special fields with particular reference to military requirements are pointed out.

  19. Dry cell battery poisoning

    Science.gov (United States)

    Batteries - dry cell ... Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries ...

  20. Fatal Case of Hydrocarbon Aspiration and Use of Lipoid Cells as Corroborative Finding for Rapid Autopsy Diagnosis in Cases of Delayed Death

    OpenAIRE

    Jaybhaye, Prasad L.; Shilawant, Santosh S.

    2014-01-01

    Accidental aspiration of diesel can cause consolidation, atelectasis, and abscess formation. Aspiration of diesel usually results into pneumonitis, which resolves completely within 5–7 days of treatment. Diesel aspiration resulting in bilateral pneumonia and death is rare and is scarcely documented in literature. Finding of lipoid cells in lung autopsy specimen is one of the important features of hydrocarbon aspiration. Unfortunately this important finding is not mentioned in most of the toxi...

  1. Fatal case of hydrocarbon aspiration and use of lipoid cells as corroborative finding for rapid autopsy diagnosis in cases of delayed death.

    Science.gov (United States)

    Jaybhaye, Prasad L; Shilawant, Santosh S

    2014-01-01

    Accidental aspiration of diesel can cause consolidation, atelectasis, and abscess formation. Aspiration of diesel usually results into pneumonitis, which resolves completely within 5-7 days of treatment. Diesel aspiration resulting in bilateral pneumonia and death is rare and is scarcely documented in literature. Finding of lipoid cells in lung autopsy specimen is one of the important features of hydrocarbon aspiration. Unfortunately this important finding is not mentioned in most of the toxicology textbooks. Hence, we are reporting this case. PMID:25948973

  2. An attempt to induce transient immunosuppression pre-erythrocytapheresis in a girl with sickle cell disease, a history of severe delayed hemolytic transfusion reactions and need for hip prosthesis

    Directory of Open Access Journals (Sweden)

    Alessandro Cattoni

    2013-06-01

    Full Text Available We report on a case of delayed hemolytic transfusion reaction (DHTR occurred 7 days after an erythrocytapheresis or eritroexchange procedure (EEX treated with rituximab and glucocorticoids in a 15-years old patient with sickle cell disease. EEX was performed despite a previous diagnosis of alloimmunization, in order to reduce hemoglobin S rate before a major surgery for avascular necrosis of the femoral head. A first dose of rituximab was administered before EEX. However, rituximab couldn’t prevent DHTR that occurred with acute hemolysis, hemoglobinuria and hyper-bilirubinemia. A further dose of rituximab and three boli of methylprednisolone were given after the onset of the reaction. It is likely that the combined use of rituximab and steroids managed to gradually improve both patient’s general conditions and hemoglobin levels. Nor early or late side effects were registered in a 33-months follow-up period. This report suggests the potential effectiveness and safety of rituximab in combination with steroids in managing and mitigating the symptoms of delayed post-transfusional hemolytic reactions in alloimmunized patients affected by sickle cell disease with absolute need for erythrocytapheresis.

  3. Cell sorting by deterministic cell rolling

    OpenAIRE

    Choi, Sungyoung; Karp, Jeffrey M.; Karnik, Rohit

    2011-01-01

    This communication presents the concept of “deterministic cell rolling”, which leverages transient cell-surface molecular interactions that mediate cell rolling to sort cells with high purity and efficiency in a single step.

  4. [Merkel cell skin carcinoma].

    Science.gov (United States)

    Krejcí, K; Zadrazil, J; Tichý, T; Horák, P; Ciferská, H; Hodulová, M; Zezulová, M; Zlevorová, M

    2010-01-01

    Merkel cell carcinoma is a rare tumour of the skin. It affects predominantly elderly Caucasian males on sun-exposed areas of the skin. Distinctively more frequent and at significantly lower age, its incidence is higher in immunocompromised patients. In these patients we often observe the highly aggressive course of Merkel cell carcinoma and a fatal outcome. The incidence of Merkel cell carcinoma has been rising in recent years and is more dramatic than the increased incidence of cutaneous melanoma. More than one-third of Merkel cell carcinoma patients will die from this cancer, making it twice as lethal as melanoma. The malignant transformation of Merkel cells is currently thought to be related to an infection with Merkel cell polyomavirus. In the early stage the discreet clinical picture may be contrary to extensive microscopic invasion and this seemingly benign appearance can delay diagnosis or increase the risk of insufficient tumour excision. The diagnosis is definitely confirmed by histological evaluation and immunohistochemical tests. A typical feature is the tendency of Merkel cell carcinoma to frequent local recurrence and early metastasizing into regional lymph nodes with subsequent tumour generalization. The mainstay of therapy is radical excision of the tumour and adjuvant radiotherapy targeted at the site of primary incidence and local draining lymph nodes. The efficacy of different chemotherapy protocols in Merkel cell carcinoma is limited and the median survival rate is measured in months. In the future, prophylaxis with vaccination against Merkel cell polyomavirus will hopefully be possible in high-risk patients, as well as therapeutic usage of antisense oligonucleotides or microRNAs, eventually complete Merkel cell carcinoma elimination by affecting the tumour suppressor gene Atonal homolog 1 expression. The staging of the tumour at time of diagnosis is the most important prognostic factor. In this respect, the importance of preventative skin

  5. Electrochemical cell

    Science.gov (United States)

    Nagy, Zoltan; Yonco, Robert M.; You, Hoydoo; Melendres, Carlos A.

    1992-01-01

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90.degree. in either direction while maintaining the working and counter electrodes submerged in the electrolyte.

  6. 8-60hIPP5(m)-induced G2/M cell cycle arrest involves activation of ATM/p53/p21(cip1/waf1) pathways and delayed cyclin B1 nuclear translocation.

    Science.gov (United States)

    Zeng, Qi-Yan; Zeng, Lin-Jie; Huang, Yu; Huang, Yong-Qi; Zhu, Qi-Fang; Liao, Zhi-Hong

    2014-01-01

    Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. The active mutant IPP5 (8-60hIPP5(m)), the latest member of the inhibitory molecules for PP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate the underlying mechanisms, the present study assessed overexpression of 8-60hIPP5(m) in HeLa cells. Flow cytometric and biochemical analyses showed that overexpression of 8-60hIPP5(m) induced G2/M-phase arrest, which was accompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, p21(cip1/waf1) and Cdc2, suggesting that 8-60hIPP5(m) induces G2/M arrest through activation of the ATM/p53/p21(cip1/waf1)/Cdc2/ cyclin B1 pathways. We further showed that overexpression of 8-60hIPP5(m) led to delayed nuclear translocation of cyclin B1. 8-60hIPP5(m) also could translocate to the nucleus in G2/M phase and interact with pp1α and Cdc2 as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for 8-60hIPP5(m) in regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategies for cervix carcinoma.

  7. Solar cells

    Science.gov (United States)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  8. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    In his influential essay on markets, An essay on framing and overflowing (1998), Michel Callon writes that `the growing complexity of industrialized societies [is] due in large part to the movements of the technosciences, which are causing connections and interdependencies to proliferate'. This p...... and tantalizing than stem cells, in research, in medicine, or as products.......'. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...

  9. Cell Libraries

    Science.gov (United States)

    1994-01-01

    A NASA contract led to the development of faster and more energy efficient semiconductor materials for digital integrated circuits. Gallium arsenide (GaAs) conducts electrons 4-6 times faster than silicon and uses less power at frequencies above 100-150 megahertz. However, the material is expensive, brittle, fragile and has lacked computer automated engineering tools to solve this problem. Systems & Processes Engineering Corporation (SPEC) developed a series of GaAs cell libraries for cell layout, design rule checking, logic synthesis, placement and routing, simulation and chip assembly. The system is marketed by Compare Design Automation.

  10. Solar cells

    International Nuclear Information System (INIS)

    A method of producing solar cells is described which consists of producing a substantially monocrystalline tubular body of silicon or other suitable semiconductor material, treating this body to form an annular rectifying junction and then cutting it longitudinally to form a number of nearly flat ribbons from which the solar cells are fabricated. The P=N rectifying junction produced by the formation of silicon dioxide on the layers at the inner and outer surfaces of the body can be formed by ion-implantation or diffusion. (U.K.)

  11. Learn About Stem Cells

    Science.gov (United States)

    ... PDF) Download an introduction to stem cells and stem cell research. Stem Cell Glossary Stem cell terms to know. ... ISSCR Get Involved Media © 2015 International Society for Stem Cell Research Terms of Use Disclaimer Privacy Policy

  12. Stem Cell Basics

    Science.gov (United States)

    ... Information Stem Cell Basics Stem Cell Basics: Introduction Stem Cell Information General Information Clinical Trials Funding Information Current Research Policy Glossary Site Map Stem Cell Basics Introduction: What are stem cells, and why ...

  13. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Neurons Oligodendrocyte Parthenogenesis Passage Pluripotent Polar body Preimplantation Proliferation Regenerative medicine Reproductive cloning Signals Somatic cell Somatic cell nuclear transfer (SCNT) Somatic (adult) stem cell Stem cells Stromal cells Subculturing Surface markers ...

  14. Red blood cell-incompatible allogeneic hematopoietic progenitor cell transplantation.

    Science.gov (United States)

    Rowley, S D; Donato, M L; Bhattacharyya, P

    2011-09-01

    Transplantation of hematopoietic progenitor cells from red cell-incompatible donors occurs in 30-50% of patients. Immediate and delayed hemolytic transfusion reactions are expected complications of red cell-disparate transplantation and both ABO and other red cell systems such as Kidd and rhesus can be involved. The immunohematological consequences of red cell-incompatible transplantation include delayed red blood cell recovery, pure red cell aplasia and delayed hemolysis from viable lymphocytes carried in the graft ('passenger lymphocytes'). The risks of these reactions, which may be abrupt in onset and fatal, are ameliorated by graft processing and proper blood component support. Red blood cell antigens are expressed on endothelial and epithelial tissues in the body and could serve to increase the risk of GvHD. Mouse models indicate that blood cell antigens may function as minor histocompatibility antigens affecting engraftment. Similar observations have been found in early studies of human transplantation for transfused recipients, although current conditioning and immunosuppressive regimens appear to overcome this affect. No deleterious effects from the use of red cell-incompatible hematopoietic grafts on transplant outcomes, such as granulocyte and platelet engraftments, the incidences of acute or chronic GvHD, relapse risk or OS, have been consistently demonstrated. Most studies, however, include limited number of patients, varying diagnoses and differing treatment regimens, complicating the detection of an effect of ABO-incompatible transplantation. Classification of patients by ABO phenotype ignoring the allelic differences of these antigens also may obscure the effect of red cell-incompatible transplantation on transplant outcomes. PMID:21897398

  15. Natural killer cells in leukemogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, H.J.; Stolz, W.; Sutter, H.; Kreja, L.

    1986-01-01

    In order to relate a reduced natural killer (NK) cell function to leukemogenesis, NK cells in the spleen and peritoneal exudate cells, with and without stimulation by Corynebacterium parvum, were tested in mice of various strains after split dose irradiation and after leukemogenic treatment with butyl- and methylnitrosourea. The investigations included also mice submitted to non-leukemogenic irradiation (1 x 1.5 and 1 x 4.5 Gy) and mice submitted to an additional treatment with hydrocortisone, which delays leukemia development after methylnitrosourea. There was, indeed, a NK-cell depression, but no major differences were seen between mice prone to leukemia development and those after cytotoxic, but nonleukemogenic, treatment.

  16. Photovoltaic cell

    Science.gov (United States)

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  17. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...... and nuclear fuel-based energy technologies....

  18. Potent Cells

    Science.gov (United States)

    Liu, Dennis

    2007-01-01

    It seems hard to believe that Dolly the cloned sheep was born 10 years ago, kindling furious arguments over the prospects and ethics of cloning a human. Today, the controversy over cloning is entwined, often confused, with concerns over the use of human embryonic stem cells. Most people are unclear what cloning is, and they know even less when it…

  19. Electrochemical Cell

    DEFF Research Database (Denmark)

    1999-01-01

    The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode in which the positive electrode structure comprises a lithium cobalt manganese oxide of the composition Li¿2?Co¿y?Mn¿2-y?O¿4? where 0

  20. 人参皂苷Rg1延缓造血干细胞衰老及其相关机制%Mechanism of ginsenoside Rg1 in the delayed senescence of hematopoietic stem cell

    Institute of Scientific and Technical Information of China (English)

    周玥; 杨斌; 姜蓉; 姚欣; 王亚平

    2010-01-01

    Objective To investigate the underlying mechanism of ginsenoside Rg1 in the regulation of hematopoietic stem cell (HSC) senescence so as to provide the theoretic and experimental foundations for searching the methods of how to delay its senescence. Methods Sca-1 + HSC was isolated by magnetic cell sorting (MACS) and divided into control, aged, Rg1, Rg1 treatment aged and Rg1 delayed aged groups. The cellular changes were observed by senescence-associated β-galactosidase ( SA-β-Gal ) staining. And cell cycle assay and culture of mixed hematopoietic progenitor cell were used to investigate the effect of ginsenoside Rg1 to delay Sca-1 + HSC senescence. The expressions of p16INK4a, p19Arf, p53 and p21Cipl/Wafl mRNA were detected by reverse transcription-polymerase chain reaction ( RT-PCR ). The expressions of p16INK4a, p21Cipl/Wafl , cyclinD1, cyclinE, CDK2 and CDK4 protein were examined by Western blot. Results In the Rg1 treatment and delayed aged groups, the percentage of positive SA-β-Gal-expressing cells was lower than that of the aged group [30. 1% ± 2. 4%, 21.5% ± 2. 8% vs 69. 5% ± 5. 0%]; the number of cells in G1 phase was lower than that of the aged group [81.4% ± 1. 2%, 78.2% ± 1. 4% vs 87. 5% ±4. 0%]; but the number of colony for the mixed hematopoietic progenitor was higher than that of the aged group [(8. 0 ±2. 2)/104 Sca-1 + HSC, (9. 2 ± 1. 8)/104 Sca-1 + HSC vs (3.0 ± 1. 6)/104 Sca-1 +HSC].As compared with the aged group, the expressions of p16INK4a, p19Arf, p53, p21cipl/Wafl mRNA and p16INK4a,p21Cipl/Wafl, cyclinD1 protein were down-regulated (all P < 0. 01 ) while the expressions of CDK4, CDK2and cyclinE protein up-regulated in Rg1 treatment aged and Rg1 delayed aged groups ( all P <0. 01 ). The changes of the Rg1 delayed aged group were significantly marked than those of the Rg1 treatment aged group. Conclusions Rg1 can effectively delay the t-BHP-induced senescence of HSCs. Both p16INK4a-Rb and p19Arf-p53-p21Crp/Wafl may play an

  1. Cell Docking, Movement and Cell-Cell Interactions of Heterogeneous Cell Suspensions in a Cell Manipulation Microdevice

    OpenAIRE

    Long-Sun Huang; Yu-Hung Wang; Yu-Wei Chung; Fei-Lung Lai; Shiaw-Min Hwang

    2011-01-01

    This study demonstrates a novel cell manipulation microdevice for cell docking, culturing, cell-cell contact and interaction by microfluidic manipulation of heterogeneous cell suspensions. Heterogeneous cell suspensions include disparate blood cells of natural killer cells and leukemia cancer cells for immune cell transplantation therapy. However, NK cell alloreactivity from different healthy donors present various recovery response levels. Little is still known about the interactions and cyt...

  2. MAZ-binding G4-decoy with locked nucleic acid and twisted intercalating nucleic acid modifications suppresses KRAS in pancreatic cancer cells and delays tumor growth in mice

    DEFF Research Database (Denmark)

    Cogoi, Susanna; Zorzet, Sonia; Rapozzi, Valentina;

    2013-01-01

    KRAS mutations are primary genetic lesions leading to pancreatic cancer. The promoter of human KRAS contains a nuclease-hypersensitive element (NHE) that can fold in G4-DNA structures binding to nuclear proteins, including MAZ (myc-associated zinc-finger). Here, we report that MAZ activates KRAS...... transcription. To knockdown oncogenic KRAS in pancreatic cancer cells, we designed oligonucleotides that mimic one of the G-quadruplexes formed by NHE (G4-decoys). To increase their nuclease resistance, two locked nucleic acid (LNA) modifications were introduced at the 3'-end, whereas to enhance the folding...... the Kaplan-Meier median survival time by 70%. Together, our data show that MAZ-specific G4-decoys mimicking a KRAS quadruplex are promising for pancreatic cancer therapy....

  3. Foxp3⁺ regulatory T cells delay expulsion of intestinal nematodes by suppression of IL-9-driven mast cell activation in BALB/c but not in C57BL/6 mice.

    OpenAIRE

    Birte Blankenhaus; Martina Reitz; Yannick Brenz; Marie-Luise Eschbach; Wiebke Hartmann; Irma Haben; Tim Sparwasser; Jochen Huehn; Anja Kühl; Feyerabend, Thorsten B.; Hans-Reimer Rodewald; Minka Breloer

    2014-01-01

    Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3⁺ regulatory T cells (Treg) in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg fu...

  4. Biosynthesized Platinum Nanoparticles Inhibit the Proliferation of Human Lung-Cancer Cells in vitro and Delay the Growth of a Human Lung-Tumor Xenograft in vivo -In vitro and in vivo Anticancer Activity of bio-Pt NPs-

    Directory of Open Access Journals (Sweden)

    Bendale Yogesh

    2016-06-01

    Full Text Available Objectives: Lung cancer remains a deadly disease with unsatisfactory overall survival. Cisplatin, a standard platinum (Pt-based chemotherapeutic agent, has the potential to inhibit the growth of lung cancer. Its use, however, is occasionally limited by severe organ toxicity. However, until now, no systematic study has been conducted to verify its efficacy with proper experimental support in vivo. Therefore, we examined whether biosynthesized Pt nanoparticles (NPs inhibited human lung cancer in vitro and in vivo to validate their use in alternative and complementary medicine. Methods: We evaluated the in vitro and the in vivo anticancer efficiencies of biosynthesized Pt NPs in a subcutaneous xenograft model with A549 cells. Severe combined immune deficient mice (SCID were divided into four groups: group 1 being the vehicle control group and groups 2, 3 and 4 being the experimental groups. Once the tumor volume had reached 70 ─ 75 mm3, the progression profile of the tumor growth kinetics and the body weights of the mice were measured every week for 6 weeks after oral administration of Pt NPs. Doses of Pt NPs of 500, 1,000 and 2,000 mg/kg of body weight were administered to the experimental groups and a dose of honey was administered to the vehicle control group. The efficacy was quantified by using the delay in tumor growth following the administration of Pt NPs of A549 human-lung-cancer xenografts growing in SCID mice. Results: The in vitro cytotoxicity evaluation indicated that Pt NPs, in a dose-dependent manner, inhibited the growth of A549 cells, and the in vivo evaluation showed that Pt NPs at the mid and high doses effectively inhibited and delayed the growth of lung cancer in SCID mice. Conclusion: These findings confirm the antitumor properties of biosynthesized Pt NPs and suggest that they may be a cost-effective alternative for the treatment of patients with lung cancer.

  5. Reprogrammed pluripotent stem cells from somatic cells.

    Science.gov (United States)

    Kim, Jong Soo; Choi, Hyun Woo; Choi, Sol; Do, Jeong Tae

    2011-06-01

    Pluripotent stem cells, such as embryonic stem (ES) cells, can differentiate into all cell types. So, these cells can be a biological resource for regenerative medicine. However, ES cells known as standard pluripotent cells have problem to be used for cell therapy because of ethical issue of the origin and immune response on the graft. Hence, recently reprogrammed pluripotent cells have been suggested as an alternative source for regenerative medicine. Somatic cells can acquire the ES cell-like pluripotency by transferring somatic cell nuclei into oocytes, by cell fusion with pluripotent cells. Retroviral-mediated introduction of four factors, Oct4, Sox2, Klf4 and c-Myc can successfully reprogram somatic cells into ES cell-like pluripotent stem cells, known as induced pluripotent stem (iPS) cells. These cells closely resemble ES cells in gene expression pattern, cell biologic and phenotypic characteristics. However, to reach the eventual goal of clinical application, it is necessary to overcome the major drawbacks such as low reprogramming efficiency and genomic alterations due to viral integration. In this review, we discuss the current reprogramming techniques and mechanisms of nuclear reprogramming induced by transcription factor transduction. PMID:24298328

  6. Ghost cell lesions

    Directory of Open Access Journals (Sweden)

    E Rajesh

    2015-01-01

    Full Text Available Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms.

  7. Cell transplantation for Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Jia Liu; Hongyun Huang

    2006-01-01

    OBJECTIVE: The motor symptoms of Parkinson's disease (PD) can be improved by cell transplantation,which has caught general attention from the field of the therapy for PD recently. In this paper, we summarize the cell-based therapy for PD.DATA SOURCES: A search for English literature related to the cellular transplantation of PD from January 1979to July 2006 was conducted in Medline with the key words of "Parkinson's disease, cell transplantation,embryonic stem cells, neural stem cells".STUDY SELECTTON: Data were checked in the first trial, and literatures about PD and cell transplantation were selected. Inclusive criteria: ① PD; ② Cell transplantation. Exclusive criteria: repetitive researches.DATA EXTRACTTON: A total of 100 papers related to cellular transplant and PD were collected and 41literatures were in accordance with the inclusive criteria.DATA SYNTHESIS: PD is a neural degeneration disease that threatens the health of the aged people, and most traditional therapeusis cannot delay its pathological proceeding. Cell transplantation is becoming popular as a new therapeutic tool, and the cells used to transplant mainly included dopamine-secreting cells, fetal ventral mesencephalic cells, embryonic stem cells and neural stem cells up to now. Animal experiment and clinical test demonstrate that cell transplantation can relieve the motor symptoms of Parkinson's disease obviously, but there are some problems need to be solved.CONCLUSTON: Cell transplantation has visible therapeutic efficacy on PD. Following the improvement of technique, and we have enough cause to credit that cell therapy may cure PD in the future.

  8. CASE REPORT OF LANGERHANS CELL HISTIOCYTOSIS

    Directory of Open Access Journals (Sweden)

    Umesh Reddy

    2014-08-01

    Full Text Available : Langerhans cell histiocytosis (LCH is a rare proliferative disorder in which pathological Langerhans cells (LCs accumulate in a variety of organs. This report describes a boy with Langerhans' cell histiocytosis who presented with primarily soft tissue swellings, without pain. A high index of suspicion is required to reach to a diagnosis of langerhans cell histiocytosis to prevent delay in proper management of this disease.

  9. Murine Mueller cells are progenitor cells for neuronal cells and fibrous tissue cells

    International Nuclear Information System (INIS)

    Mammalian Mueller cells have been reported to possess retinal progenitor cell properties and generate new neurons after injury. This study investigates murine Mueller cells under in vitro conditions for their capability of dedifferentiation into retinal progenitor cells. Mueller cells were isolated from mouse retina, and proliferating cells were expanded in serum-containing medium. For dedifferentiation, the cultured cells were transferred to serum-replacement medium (SRM) at different points in time after their isolation. Interestingly, early cell passages produced fibrous tissue in which extracellular matrix proteins and connective tissue markers were differentially expressed. In contrast, aged Mueller cell cultures formed neurospheres in SRM that are characteristic for neuronal progenitor cells. These neurospheres differentiated into neuron-like cells after cultivation on laminin/ornithine cell culture substrate. Here, we report for the first time that murine Mueller cells can be progenitors for both, fibrous tissue cells and neuronal cells, depending on the age of the cell culture

  10. Sickle Cell Information Center

    Science.gov (United States)

    ... Around the Web Google Custom Search – sickle cell Sickle Cell Anemia - In-Depth Report - NY Times Health January 18, 1970 Sickle cell disease (also called sickle cell anemia) is an inherited blood disorder that affects red ...

  11. Electrorefining cell evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bronson, M.C.; Thomas, R.L. (ed.)

    1989-04-14

    Operational characteristics of the LANL electrorefining cell, a modified LANL electrorefining cell, and an advanced electrorefining cell (known as the CRAC cell) were determined. Average process yields achieved were: 75% for the LANL cell, 82% for the modified LANL cell, and 86% for the CRAC cell. All product metal from the LANL and modified LANL cells was within foundry specifications. Metal from one run in the CRAC cell exceeded foundry specifications for tantalum. The LANL and modified LANL cells were simple in design and operation, but product separation was more labor intensive than with the CRAC cell. The CRAC cell was more complicated in design but remained relatively simple in operation. A decision analysis concluded that the modified LANL cell was the preferred cell. It was recommended that the modified LANL cell be implemented by the Plutonium Recovery Project at Rocky Flats and that development of the CRAC cell continue. 8 refs., 22 figs., 12 tabs.

  12. HIGH SPEED KERR CELL FRAMING CAMERA

    Science.gov (United States)

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  13. What are Stem Cells?

    OpenAIRE

    Ahmadshah Farhat; Ashraf Mohammadzadeh; M. Rezaie

    2014-01-01

      Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem ...

  14. Pluripotent stem cell lines

    OpenAIRE

    Yu, Junying; Thomson, James A.

    2008-01-01

    The derivation of human embryonic stem cells 10 years ago ignited an explosion of public interest in stem cells, yet this achievement depended on prior decades of research on mouse embryonic carcinoma cells and embryonic stem cells. In turn, the recent derivation of mouse and human induced pluripotent stem cells depended on the prior studies on mouse and human embryonic stem cells. Both human embryonic stem cells and induced pluripotent stem cells can self-renew indefinitely in vitro while ma...

  15. Active oxygen and cell death in cereal aleurone cells.

    Science.gov (United States)

    Fath, Angelika; Bethke, Paul; Beligni, Veronica; Jones, Russell

    2002-05-01

    The cereal aleurone layer is a secretory tissue whose function is regulated by gibberellic acid (GA) and abscisic acid (ABA). Aleurone cells lack functional chloroplasts, thus excluding photosynthesis as a source of active oxygen species (AOS) in cell death. Incubation of barley aleurone layers or protoplasts in GA initiated the cell death programme, but incubation in ABA delays programmed cell death (PCD). Light, especially blue and UV-A light, and H(2)O(2) accelerate PCD of GA-treated aleurone cells, but ABA-treated aleurone cells are refractory to light and H(2)O(2) and are not killed. It was shown that light elevated intracellular H(2)O(2), and that the rise in H(2)O(2) was greater in GA-treated cells compared to cells in ABA. Experiments with antioxidants show that PCD in aleurone is probably regulated by AOS. The sensitivity of GA-treated aleurone to light and H(2)O(2) is a result of lowered amounts of enzymes that metabolize AOS. mRNAs encoding catalase, ascorbate peroxidase and superoxide dismutase are all reduced during 6-18 h of incubation in GA, but these mRNAs were present in higher amounts in cells incubated in ABA. The amounts of protein and enzyme activities encoded by these mRNAs were also dramatically reduced in GA-treated cells. Aleurone cells store and metabolize neutral lipids via the glyoxylate cycle in response to GA, and glyoxysomes are one potential source of AOS in the GA-treated cells. Mitochondria are another potential source of AOS in GA-treated cells. AOS generated by these organelles bring about membrane rupture and cell death.

  16. DNA-cell conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  17. Molecular Mechanisms of Cell-cell Recognition

    Institute of Scientific and Technical Information of China (English)

    WANG Jia-Huai

    2004-01-01

    Cell-cell recognition is the key for multicellular organisms to survive. This recognition critically depends on protein-protein interactions from opposing cell surfaces. Recent structural investigations reveal unique features of these cell surface receptors and how they interact. These interactions are specific, but usually relatively weak, with more hydrophilic forces involved in binding. The receptors appear to have specialized ways to present their key interacting elements for ligand-binding from the cell surface. Cell-cell contacts are multivalent. A large group of cell surface molecules are engaged in interactions. Characteristic weak interactions make possible for each individual molecule pair within the group to constantly associate-dissociate-reassociate, such that the cell-cell recognition becomes a dynamic process. The immunological synapse is a good example for immune receptors to be orchestrated in performing immunological function in a collective fashion.

  18. First Delayed Resection Findings After Irreversible Electroporation (IRE) of Human Localised Renal Cell Carcinoma (RCC) in the IRENE Pilot Phase 2a Trial

    International Nuclear Information System (INIS)

    IntroductionIt is postulated that focal IRE affords complete ablation of soft-tissue tumours while protecting the healthy peritumoral tissue. Therefore, IRE may be an interesting option for minimally invasive, kidney-tissue-sparing, non-thermal ablation of renal tumours.AimWith this current pilot study (“IRENE trial”), we present the first detailed histopathological data of IRE of human RCC followed by delayed tumour resection. The aim of this interim analysis of the first three patients was to investigate the ablation efficiency of percutaneous image-guided focal IRE in RCC, to assess whether a complete ablation of T1a RCC and tissue preservation with the NanoKnife system is possible and to decide whether the ablation parameters need to be altered.MethodsFollowing resection 4 weeks after percutaneous IRE, the success of ablation and detailed histopathological description were used to check the ablation parameters.ResultsThe IRE led to a high degree of damage to the renal tumours (1 central, 2 peripheral; size range 15–17 mm). The postulated homogeneous, isomorphic damage was only partly confirmed. We found a zonal structuring of the ablation zone, negative margins and, enclosed within the ablation zone, very small tumour residues of unclear malignancy.ConclusionAccording to these initial, preliminary study results of the first three renal cases, a new zonal distribution of IRE damage was described and the curative intended, renal saving focal ablation of localised RCC below <3 cm by percutaneous IRE by the NanoKnife system appears to be possible, but needs further, systematic evaluation for this treatment method and treatment protocol

  19. First Delayed Resection Findings After Irreversible Electroporation (IRE) of Human Localised Renal Cell Carcinoma (RCC) in the IRENE Pilot Phase 2a Trial

    Energy Technology Data Exchange (ETDEWEB)

    Wendler, Johann Jakob, E-mail: johann.wendler@med.ovgu.de [Otto von Guericke University of Magdeburg, Department of Urology, University Hospital (Germany); Ricke, Jens, E-mail: jens.Ricke@med.ovgu.de; Pech, Maciej, E-mail: macej.pech@med.ovgu.de; Fischbach, Frank, E-mail: frank.fischbach@med.ovgu.de; Jürgens, Julian, E-mail: julian.juergens@med.ovgu.de [University of Magdeburg, Department of Radiology (Germany); Siedentopf, Sandra, E-mail: sandra.siedentopf@med.ovgu.de; Roessner, Albert, E-mail: albert.roessner@med.ovgu.de [University of Magdeburg, Institute of Pathology (Germany); Porsch, Markus, E-mail: markus.porsch@med.ovgu.de; Baumunk, Daniel, E-mail: daniel.baumunk@med.ovgu.de; Schostak, Martin, E-mail: martin.schostak@med.ovgu.de [Otto von Guericke University of Magdeburg, Department of Urology, University Hospital (Germany); Köllermann, Jens, E-mail: jens.koellermann@sana.de [Sana Klinikum Offenbach Am Main, Institute of Pathology (Germany); Liehr, Uwe-Bernd, E-mail: uwe-bernd.liehr@med.ovgu.de [Otto von Guericke University of Magdeburg, Department of Urology, University Hospital (Germany)

    2016-02-15

    IntroductionIt is postulated that focal IRE affords complete ablation of soft-tissue tumours while protecting the healthy peritumoral tissue. Therefore, IRE may be an interesting option for minimally invasive, kidney-tissue-sparing, non-thermal ablation of renal tumours.AimWith this current pilot study (“IRENE trial”), we present the first detailed histopathological data of IRE of human RCC followed by delayed tumour resection. The aim of this interim analysis of the first three patients was to investigate the ablation efficiency of percutaneous image-guided focal IRE in RCC, to assess whether a complete ablation of T1a RCC and tissue preservation with the NanoKnife system is possible and to decide whether the ablation parameters need to be altered.MethodsFollowing resection 4 weeks after percutaneous IRE, the success of ablation and detailed histopathological description were used to check the ablation parameters.ResultsThe IRE led to a high degree of damage to the renal tumours (1 central, 2 peripheral; size range 15–17 mm). The postulated homogeneous, isomorphic damage was only partly confirmed. We found a zonal structuring of the ablation zone, negative margins and, enclosed within the ablation zone, very small tumour residues of unclear malignancy.ConclusionAccording to these initial, preliminary study results of the first three renal cases, a new zonal distribution of IRE damage was described and the curative intended, renal saving focal ablation of localised RCC below <3 cm by percutaneous IRE by the NanoKnife system appears to be possible, but needs further, systematic evaluation for this treatment method and treatment protocol.

  20. nduced pluripotent stem cells and cell therapy

    Directory of Open Access Journals (Sweden)

    Banu İskender

    2013-12-01

    Full Text Available Human embryonic stem cells are derived from the inner cell mass of a blastocyst-stage embryo. They hold a huge promise for cell therapy with their self-renewing ability and pluripotency, which is known as the potential to differentiate into all cell types originating from three embryonic germ layers. However, their unique pluripotent feature could not be utilised for therapeutic purposes due to the ethical and legal problems during derivation. Recently, it was shown that the cells from adult tissues could be reverted into embryonic state, thereby restoring their pluripotent feature. This has strenghtened the possiblity of directed differentition of the reprogrammed somatic cells into the desired cell types in vitro and their use in regenerative medicine. Although these cells were termed as induced pluripotent cells, the mechanism of pluripotency has yet to be understood. Still, induced pluripotent stem cell technology is considered to be significant by proposing novel approaches in disease modelling, drug screening and cell therapy. Besides their self-renewing ability and their potential to differentiate into all cell types in a human body, they arouse a great interest in scientific world by being far from the ethical concerns regarding their embryonic counterparts and their unique feature of being patient-specific in prospective cell therapies. In this review, induced pluripotent stem cell technology and its role in cell-based therapies from past to present will be discussed. J Clin Exp Invest 2013; 4 (4: 550-561

  1. Modeling cell-in-cell structure into its biological significance

    OpenAIRE

    He, M-f; S. Wang; Wang, Y.; Wang, X-N.

    2013-01-01

    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ‘entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  2. Monitoring cell growth.

    Science.gov (United States)

    Strober, W

    2001-05-01

    This appendix provides two protocols for monitoring cell growth. Counting cells using a hemacytometer is tedious but it allows one to effectively distinguish live cells from dead cells (using Trypan Blue exclusion). In addition, this procedure is less subject to errors due to cell clumping or heterogeneity of cell size. The use of an electronic cell counter is quicker and easier than counting cells using a hemacytometer. However, an electronic cell counter as currently constructed does not distinguish live from dead cells in a reliable fashion and is subject to error due to the presence of cell clumps. Overall, the electronic cell counter is best reserved for repetitive and rapid counting of fresh peripheral blood cells and should be used with caution when counting cell populations derived from tissues. PMID:18432653

  3. Automated Cell-Cutting for Cell Cloning

    Science.gov (United States)

    Ichikawa, Akihiko; Tanikawa, Tamio; Matsukawa, Kazutsugu; Takahashi, Seiya; Ohba, Kohtaro

    We develop an automated cell-cutting technique for cell cloning. Animal cells softened by the cytochalasin treatment are injected into a microfluidic chip. The microfluidic chip contains two orthogonal channels: one microchannel is wide, used to transport cells, and generates the cutting flow; the other is thin and used for aspiration, fixing, and stretching of the cell. The injected cell is aspirated and stretched in the thin microchannel. Simultaneously, the volumes of the cell before and after aspiration are calculated; the volumes are used to calculate the fluid flow required to aspirate half the volume of the cell into the thin microchannel. Finally, we apply a high-speed flow in the orthogonal microchannel to bisect the cell. This paper reports the cutting process, the cutting system, and the results of the experiment.

  4. [Therapeutic use of stem cells. II. Adult stem cells].

    Science.gov (United States)

    Uzan, Georges

    2004-09-30

    Many degenerative diseases are not curable by means of classical medicine. The long term objective of cell therapy is to treat the patients with their own stem cells that could be either purified from the diseased organ or from "reservoirs" of stem cells such as that constituted by the bone marrow. The existence of stem cells in the organs or reservoirs is now established in vitro and in some cases, in animal models. Numbers of technical problems linked to the scarcity of these cells still delay the clinical use of purified stem cells. However, clinical protocols using heterogeneous cell populations have already started to treat a growing number of diseases. In some case, autologous cells can be used, as it is the case for bone marrow transplantation in blood diseases. Mesenchymal cells, also purified from the bone marrow are currently used in orthopaedic diseases. Because these cells reveal a broad differentiation potential, active research programs explore their possible use for treatment of other diseases. Bone marrow also contains vascular stem cells that could be active in reappearing defective vessels responsible for ischaemic diseases. Indeed, clinical trials in which bone marrow cells are injected in the cardiac muscle of patients with myocardial infarction or in the leg muscle (gastrocnemius) of patients with hind limb ischaemia have already started. Artificial skin prepared from skin biopsies is used for the reconstitution of the derma of severely burned patients. Clinical trials have also started, using allogenic cells. The patients must be treated by immunosuppressive drugs. Neurodegenerative diseases such as Parkinson have been successfully treated by intra-cerebral injection of foetal neurones. Pancreatic islets implanted in the liver have shown to re-establish a normal glycaemia in diabetic patients. However, all these clinical trials use differentiated cells or at least progenitors which display differentiation potential and lifetime much more

  5. Dose-rate effects in mammalian cells in culture. III. Comparison of cell killing and cell proliferation during continuous irradiation for six different cell lines

    International Nuclear Information System (INIS)

    The effects of continuous irradiation over a wide range of dose rates were studied for six different mammalian cell lines in regard to cell survival and proliferation. Cell lines were chosen in which such characteristics as population doubling time, chromosome number, DNA content, acute dose-survival curve parameters, and division delay were as diverse as possible. There was no correlation between the minimum dose rate necessary to stop cell population growth and any of the above listed characteristics, with the exception of division delay following acute doses. In general, the longer the division delay (min/rad), the lower the dose rate required to stop cell population growth. The effects of cell-cycle redistribution during continuous irradiaton in regard to cell survival were dramatic. In some cases a reduction in dose rate resulted in an increase in cell killing for a given total dose. This occurred only when dose rates were sufficient to stop cell population growth and after exposure times sufficient to allow for the occurrence of cell-cycle redistribution

  6. Sickle Cell Anemia

    Science.gov (United States)

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells are shaped like a crescent or sickle. They ... last as long as normal, round red blood cells. This leads to anemia. The sickle cells also ...

  7. Regenerative cells for transplantation in hepatic failure.

    Science.gov (United States)

    Ishikawa, Tetsuya; Banas, Agnieszka; Teratani, Takumi; Iwaguro, Hideki; Ochiya, Takahiro

    2012-01-01

    Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells have an enormous potential; however, their potential clinical application is being arrested due to various limitations such as teratoma formation followed by tumorigenesis, emergent usage, and the quality control of cells, as well as safety issues regarding long-term culture are also delaying their clinical application. In addition, human ES cells have two crucial issues: immunogenicity and ethical issues associated with their clinical application. The efficient generation of human iPS cells requires gene transfer, yet the mechanism underlying pluripotent stem cell induction has not yet been fully elucidated. Otherwise, although human adult regenerative cells including mesenchymal stem cells have a limited capacity for differentiation, they are nevertheless promising candidates for tissue regeneration in a clinical setting. This review highlights the use of regenerative cells for transplantation in hepatic failure.

  8. CELL RESEARCH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    REVIEWSInducible resistance to Fas-mediated apoptosis in B cells…………………………………ROTHSTEIN Thomas L (245)Executionary pathway for apoptosis: lessons from mutant mice………………………………………WOO Minna, Razqallah Hakem, Tak W Mak (267)The SHP-2 tyrosine phosphatase: Signaling mechanisms and biological functions…………………………………QU Cheng Kui (279)REGULAR ARTICLESTemperature dependent expression of cdc2 and cyclin B1 in spermatogenic cells during spermatogenesis…………………………KONG Wei Hua, Zheng GU, Jining LU, Jiake TSO (289)Transgenic mice overexpressing γ-aminobutyric acid transporter subtype I develop obesity…………………………………MA Ying Hua, Jia Hua HU, Xiao Gang ZHOU, Ruo Wang ZENG, Zhen Tong MEI, Jian FEI, Li He GUO (303)Genetic aberration in primary hepatocellular carcinoma: correlation between p53 gene mutation and loss-of-heterozygosity on chromosome 16q21-q23 and 9p21-p23………………………………………WANG Gang, Chang Hui HUANG, Yan ZHAO, Ling CAI, Ying WANG, Shi Jin XIU, Zheng Wen JIANG, Shuang YANG, Xin Tai ZHAO, Wei HUANG, Jian Ren GU (311)Identification and genetic mapping of four novel genes that regulate leaf deve- lopment in Arabidopsis………………………………………………SUN Yue, Wei ZHANG, Feng Ling LI, Ying Li GUO, Tian Lei LIU, Hai HUANG (325)NOTICE FOR CONTRIBUTORS…………………………………(337)CONTENTS of Vol. 10, 2000…………………………………………………(338)

  9. Cell Membrane Softening in Cancer Cells

    Science.gov (United States)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  10. Sickle cell anemia - resources

    Science.gov (United States)

    Resources - sickle cell anemia ... The following organizations are good resources for information on sickle cell anemia : American Sickle Cell Anemia Association -- www.ascaa.org National Heart, Blood, and Lung Institute -- www. ...

  11. Sickle Cell Disease

    Science.gov (United States)

    ... in Sickle Cell Disease New supplement from the American Journal of Preventive Medicine describes the state of sickle cell disease related care in the United States. Read Supplement » ... are affected by sickle cell disease. More WEBINAR ...

  12. Sickle Cell Disease

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Sickle Cell Disease? Español The term sickle cell disease (SCD) ... common forms of SCD. Some Forms of Sickle Cell Disease Hemoglobin SS Hemoglobin SC Hemoglobin Sβ 0 thalassemia ...

  13. Squamous cell skin cancer

    Science.gov (United States)

    ... earliest form of squamous cell cancer is called Bowen disease (or squamous cell carcinoma in situ). This type ... cancer; Squamous cell carcinoma of the skin Images Bowen's disease on the hand Keratoacanthoma Keratoacanthoma Skin cancer, squamous ...

  14. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC ...

  15. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL) Provides testing for technology readiness of fuel cell systems The FCL investigates, tests and verifies the performance of fuel-cell systems...

  16. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  17. Basal Cell Carcinoma (BCC)

    Science.gov (United States)

    ... epithelioma, is the most common form of skin cancer. Basal cell carcinoma usually occurs on sun-damaged skin, especially ... other health issues. Infiltrating or morpheaform basal cell carcinomas: Infiltrating basal cell carcinomas can be more aggressive and locally destructive ...

  18. Immobilization of cells via activated cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Markt, M.; Kas, J.; Valentova, O.; Demnerova, K.; Vodrazka, Z.

    1986-10-01

    Cell walls of Saccharomyces cerevisiae and S. uvarum were activated by periodate oxidation of vicinal diol groups in cell wall polysaccharides. The aldehyde groups thus generated allow the yeast cells to be covalently bound to modified bead cellulose or macroporous glycidyl methacrylate supports, or to enzymes such as glucose oxidase and catalase. 6 references.

  19. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  20. Cell aggregation and sedimentation.

    Science.gov (United States)

    Davis, R H

    1995-01-01

    The aggregation of cells into clumps or flocs has been exploited for decades in such applications as biological wastewater treatment, beer brewing, antibiotic fermentation, and enhanced sedimentation to aid in cell recovery or retention. More recent research has included the use of cell aggregation and sedimentation to selectively separate subpopulations of cells. Potential biotechnological applications include overcoming contamination, maintaining plasmid-bearing cells in continuous fermentors, and selectively removing nonviable hybridoma cells from perfusion cultures.

  1. Artificial Stem Cell Niches

    OpenAIRE

    Lutolf, Matthias P.; Blau, Helen M.

    2009-01-01

    Stem cells are characterized by their dual ability to reproduce themselves (self-renew) and specialize (differentiate), yielding a plethora of daughter cells that maintain and regenerate tissues. In contrast to their embryonic counterparts, adult stem cells retain their unique functions only if they are in intimate contact with an instructive microenvironment, termed stem cell niche. In these niches, stem cells integrate a complex array of molecular signals that, in concert with induced cell-...

  2. Fish Stem Cell Cultures

    OpenAIRE

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is th...

  3. Stem Cell Separation Technologies

    OpenAIRE

    Zhu, Beili; Murthy, Shashi K

    2013-01-01

    Stem cell therapy and translational stem cell research require large-scale supply of stem cells at high purity and viability, thus leading to the development of stem cell separation technologies. This review covers key technologies being applied to stem cell separation, and also highlights exciting new approaches in this field. First, we will cover conventional separation methods that are commercially available and have been widely adapted. These methods include Fluorescence-activated cell so...

  4. Cell control report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This extensive report provides an essential overview of cells and their use as factory automation building blocks. The following issues are discussed in depth: Cell integration Cell software and standards Future technologies applied to cells Plus Cell control applications including: - rotary parts manufacturing - diesel engine component development - general cell control development at the General Electric Corporation - a vendor list.

  5. Fusion with stem cell makes the hepatocellular carcinoma cells similar to liver tumor-initiating cells

    OpenAIRE

    Wang, Ran; Chen, Shuxun; Li, Changxian; Ng, Kevin Tak Pan; Kong, Chi-Wing; Cheng, Jinping; Cheng, Shuk Han; Li, Ronald A.; Lo, Chung Mau; Man, Kwan; Sun, Dong

    2016-01-01

    Background Cell fusion is a fast and highly efficient technique for cells to acquire new properties. The fusion of somatic cells with stem cells can reprogram somatic cells to a pluripotent state. Our research on the fusion of stem cells and cancer cells demonstrates that the fused cells can exhibit stemness and cancer cell-like characteristics. Thus, tumor-initiating cell-like cells are generated. Methods We employed laser-induced single-cell fusion technique to fuse the hepatocellular carci...

  6. DNA damaging and cell cycle effects of the topoisomerase I poison camptothecin in irradiated human cells

    International Nuclear Information System (INIS)

    This study addressed the potential radiosensitizing and DNA-damaging actions of the DNA topoisomerase I poison camptothecin (CPT) on SV40 transformed normal (MRC5CVI) and ataxia-telangiectasia (AT5BIVA) fibroblast cell lines. In both cell lines CPT induced a dose-dependent delay of cells in S phase, followed by a dose-dependent trapping in G2/M phase. Acute X-irradiation produced patterns of G2/M arrest and S-phase delay similar to those observed for CPT in the MRC5CVI cell line, but no S phase delay was observed in the AT5BIVA cell line consistent with the ataxia-telangiectasia phenotype of this cell line. X-irradiation of CPT-treated cells resulted in additive prolongation of S phase delay in MRC5CVI cultures and additive effects for cell killing in both cell lines. The potential for topoisomerase I-DNA cross-linking by CPT was not altered by 24 h pretreatment with CPT, or by acute X-irradiation. Hypersensitivity of AT5BIVA to CPT was not attributable to elevated levels of complex trapping. (author)

  7. Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Felthaus, O. [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany); Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Ettl, T.; Gosau, M.; Driemel, O. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Brockhoff, G. [Department of Gynecology and Obstetrics, University of Regensburg (Germany); Reck, A. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Zeitler, K. [Institute of Pathology, University of Regensburg (Germany); Hautmann, M. [Department of Radiotherapy, University of Regensburg (Germany); Reichert, T.E. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Schmalz, G. [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany); Morsczeck, C., E-mail: christian.morsczeck@klinik.uni-regensburg.de [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany)

    2011-04-01

    Research highlights: {yields} Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). {yields} Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. {yields} Monoclonal cell lines showed reduced sensitivity for Paclitaxel. {yields} In situ CD133{sup +} cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. {yields} CD133{sup +} and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133{sup +} cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.

  8. Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

    International Nuclear Information System (INIS)

    Research highlights: → Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). → Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. → Monoclonal cell lines showed reduced sensitivity for Paclitaxel. → In situ CD133+ cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. → CD133+ and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133+ cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.

  9. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  10. SMOOTH MUSCLE STEM CELLS

    Science.gov (United States)

    Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

  11. Sickle Cell Disease

    Science.gov (United States)

    ... sickle cell disease? Sickle cell disease, also called sickle cell anemia, is a hereditary condition (which means it runs ... or blocks blood and oxygen reaching nearby tissues. Sickle cell disease ... the whites of the eyes) Anemia (the decreased ability of the blood to carry ...

  12. When Blood Cells Bend: Understanding Sickle Cell Disease

    Science.gov (United States)

    ... please review our exit disclaimer . Subscribe When Blood Cells Bend Understanding Sickle Cell Disease For people who don’t suspect they ... Cells Bend Wise Choices Links Living with Sickle Cell Disease See a sickle cell disease expert regularly. ...

  13. Ganglion cell like cells, diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Anand Shankar Ammanagi

    2013-01-01

    Full Text Available We report a case of cutaneous swelling found on the left anterior axillary fold of a 41-year-old man. Gross examination of specimen excised from the dermis showed a well-circumscribed nodule histologically composed of spindle cells with interspersed ganglion cell like cells. On hematoxylin and eosine (H and E staining it was diagnosed as ganglioneuroma. Ganglioneuromas are rare, benign, fully differentiated tumors that contain mature schwann cells, ganglion cells, fibrous tissue, and nerve fibers. They are commonly found along the paravertebral sympathetic ganglia and sometimes in the adrenal medulla. However primary cutaneous ganglioneuroma is an extremely rare tumor. Immunohistochemical workup revealed a fibroblastic origin and hence the case was diagnosed as fibromatosis with ganglion cell like fibroblasts. This case report suggests that the features considered diagnostic of ganglioneuromas can occur in other cutaneous lesions and, therefore, this diagnosis cannot be offered only on the basis of H and E.

  14. Cell fusion of bone marrow cells and somatic cell reprogramming by embryonic stem cells

    OpenAIRE

    Bonde, Sabrina; Pedram, Mehrdad; Stultz, Ryan; Zavazava, Nicholas

    2010-01-01

    Bone marrow transplantation is a curative treatment for many diseases, including leukemia, autoimmune diseases, and a number of immunodeficiencies. Recently, it was claimed that bone marrow cells transdifferentiate, a much desired property as bone marrow cells are abundant and therefore could be used in regenerative medicine to treat incurable chronic diseases. Using a Cre/loxP system, we studied cell fusion after bone marrow transplantation. Fused cells were chiefly Gr-1+, a myeloid cell mar...

  15. Hepatic stem cell niches

    OpenAIRE

    Kordes, Claus; Häussinger, Dieter

    2013-01-01

    Stem cell niches are special microenvironments that maintain stem cells and control their behavior to ensure tissue homeostasis and regeneration throughout life. The liver has a high regenerative capacity that involves stem/progenitor cells when the proliferation of hepatocytes is impaired. In recent years progress has been made in the identification of potential hepatic stem cell niches. There is evidence that hepatic progenitor cells can originate from niches in the canals...

  16. Stem Cell Networks

    OpenAIRE

    Werner, Eric

    2016-01-01

    We present a general computational theory of stem cell networks and their developmental dynamics. Stem cell networks are special cases of developmental control networks. Our theory generates a natural classification of all possible stem cell networks based on their network architecture. Each stem cell network has a unique topology and semantics and developmental dynamics that result in distinct phenotypes. We show that the ideal growth dynamics of multicellular systems generated by stem cell ...

  17. Stem cell mechanobiology

    OpenAIRE

    David A. Lee; Knight, Martin M.; Jonathan J Campbell; Bader, Dan L.

    2010-01-01

    Stem cells are undifferentiated cells that are capable of proliferation, self-maintenance and differentiation towards specific cell phenotypes. These processes are controlled by a variety of cues including physicochemical factors associated with the specific mechanical environment in which the cells reside. The control of stem cell biology through mechanical factors remains poorly understood and is the focus of the developing field of mechanobiology. This review provides an insight into the c...

  18. Embryonic Stem Cell Markers

    OpenAIRE

    Lan Ma; Liang Li; Wenxiu Zhao; Xiang Ji; Fangfang Zhang

    2012-01-01

    Embryonic stem cell (ESC) markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other type...

  19. Limbal stem cell transplantation

    OpenAIRE

    Fernandes Merle; Sangwan Virender; Rao Srinivas; Basti Surendra; Sridhar Mittanamalli; Bansal Aashish; Dua Harminder

    2004-01-01

    The past two decades have witnessed remarkable progress in limbal stem cell transplantation. In addition to harvesting stem cells from a cadaver or a live related donor, it is now possible to cultivate limbal stem cells in vitro and then transplant them onto the recipient bed. A clear understanding of the basic disease pathology and a correct assessment of the extent of stem cell deficiency are essential. A holistic approach towards management of limbal stem cell deficiency is needed. This ...

  20. Intraoperative Stem Cell Therapy

    OpenAIRE

    Coelho, Mónica Beato; Cabral, Joaquim M. S.; Karp, Jeffrey M.

    2012-01-01

    Stem cells hold significant promise for regeneration of tissue defects and disease-modifying therapies. Although numerous promising stem cell approaches are advancing in clinical trials, intraoperative stem cell therapies offer more immediate hope by integrating an autologous cell source with a well-established surgical intervention in a single procedure. Herein, the major developments in intraoperative stem cell approaches, from in vivo models to clinical studies, are reviewed, and the poten...

  1. The leukemic stem cell

    OpenAIRE

    Jordan, Craig T.

    2007-01-01

    Malignant stem cells have recently been described as the source of several types of human cancer. These unique cell types are typically rare and possess properties that are distinct from most other tumor cells. The properties of leukemic stem cells indicate that current chemotherapy drugs will not be effective. The use of current cytotoxic agents is not effective in leukemia because the agents target both the leukemic and normal stem cell populations. Consequently, new strategies are required...

  2. Cancer Stem Cells

    OpenAIRE

    Katarzyna Wieczorek; Jolanta Niewiarowska

    2008-01-01

    Cancer stem cell theory gains increasingly greater significance in the world of medicine. Numerous findings of scientific research in vivo and in vitro indicate that it is the population of undifferentiated, self-renewing cells which is responsible for recurrence of cancer and metastasis. Similarly to normal stem cells, cancer stem cells (CSC) function in the environment of the other cells of the organism, called the niche, where they receive signals for differentiation and proliferation proc...

  3. The cell cycle as a brake for β-cell regeneration from embryonic stem cells

    OpenAIRE

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-01

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle ...

  4. Mechanically facilitated cell-cell electrofusion.

    OpenAIRE

    Jaroszeski, M. J.; Gilbert, R.; Fallon, P.G.; Heller, R

    1994-01-01

    Apparatus and methods were developed to enable mechanically facilitated cell-cell electrofusion to be performed. The apparatus and methods mechanically place cells in contact before fusion. The key component of this fusion system was a newly developed fusion chamber. The chamber was composed of two functionally identical electrodes that were housed in a multi-layer structure. The layers functioned as support for the electrodes. They also allowed adjustment of the distance between opposing ele...

  5. Optimizing stem cell culture.

    Science.gov (United States)

    van der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

    2010-11-01

    Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. In the past few years, major efforts have been made to define more precisely the medium composition in which stem cells grow or differentiate. This led to the progressive replacement of ill-defined additives such as serum or feeder cell layers by recombinant cytokines or growth factors. Another example is the control of the oxygen pressure. For many years cell cultures have been done under atmospheric oxygen pressure which is much higher than the one experienced by stem cells in vivo. A consequence of cell metabolism is that cell culture conditions are constantly changing. Therefore, the development of high sensitive monitoring processes and control algorithms is required for ensuring cell culture medium homeostasis. Stem cells also sense the physical constraints of their microenvironment. Rigidity, stiffness, and geometry of the culture substrate influence stem cell fate. Hence, nanotopography is probably as important as medium formulation in the optimization of stem cell culture conditions. Recent advances include the development of synthetic bioinformative substrates designed at the micro- and nanoscale level. On going research in many different fields including stem cell biology, nanotechnology, and bioengineering suggest that our current way to culture cells in Petri dish or flasks will soon be outdated as flying across the Atlantic Ocean in the Lindbergh's plane. PMID:20803548

  6. Living with Sickle Cell Disease

    Science.gov (United States)

    ... sickle cell disease, go to the Health Topics Sickle Cell Anemia article. Living With and Managing Sickle Cell Disease ( ... the most severe form of sickle cell disease, sickle cell anemia, Tiffany has lived with the symptoms and complications ...

  7. What Causes Sickle Cell Disease?

    Science.gov (United States)

    ... sickle cell disease, go to the Health Topics Sickle Cell Anemia article. Living With and Managing Sickle Cell Disease ( ... the most severe form of sickle cell disease, sickle cell anemia, Tiffany has lived with the symptoms and complications ...

  8. ASYNCHRONOUS MEASUREMENT OF CDV IN ATM NETWORKS USING OAM CELLS

    Directory of Open Access Journals (Sweden)

    J. GARCÍA-HERNÁNDEZ

    2003-09-01

    Full Text Available The synchronisation between source and destination clocks at network nodes to a common reference time of day is important in order to achieve accurate measurements of cells delays in ATM networks. Otherwise, direct measurement of the cell transfer delay and cell delay variation using time-stamped OAM cells would be inaccurate. In this work, a method for the accurate measurement of cell delay variation using OAM cells, which does not rely on synchronised clocks at the measurement points is presented. This is achieved by assuming that each ATM switch has the capability to process and to modify the information contained in the OAM cells. The system presented here was modelled by means of a block-oriented network simulator (BONeS, which is a graphically-oriented, general-purpose simulation language for modelling and simulating communications networks, including ATM networks. The measurements of the cell delay variation were carried out on a VBR video source generated by a real MPEG-2 encoder with a fixed quantizer step size. The simulation results obtained show that measurements of the cumulative cell delay variation carried out without synchronised clocks at the measurement points were very closed to those obtained using synchronised clocks at the measurement points.

  9. Myeloid Cells' Evasion of Melanoma Immunity

    Science.gov (United States)

    Wang, Jun; Chen, Lieping

    2015-01-01

    An immune-suppressive role of myeloid-derived suppressor cells (MDSCs) in melanoma has long been speculated, whereas molecular mechanisms underlying this role are not well understood. Here, Chung and colleagues show that dendritic cell-associated, heparan sulfate proteoglycans-dependent integrin ligand (DC-HIL), a cell surface immune-modulatory molecule, is highly expressed on tumor-associated MDSCs. Genetic ablation or antibody blockade of DC-HIL delays the growth of transplantable B16 melanoma in syngeneic mice, which is accompanied by enhanced antitumor T-cell activities. These findings support a role for DC-HIL in immune evasion within the melanoma microenvironment. PMID:25318429

  10. Telomere Cap Components Influence the Rate of Senescence in Telomerase-Deficient Yeast Cells

    OpenAIRE

    Enomoto, Shinichiro; Glowczewski, Lynn; Lew-Smith, Jodi; Berman, Judith G.

    2004-01-01

    Cells lacking telomerase undergo senescence, a progressive reduction in cell division that involves a cell cycle delay and culminates in “crisis,” a period when most cells become inviable. In telomerase-deficient Saccharomyces cerevisiae cells lacking components of the nonsense-mediated mRNA decay (NMD) pathway (Upf1,Upf2, or Upf3 proteins), senescence is delayed, with crisis occurring ∼10 to 25 population doublings later than in Upf+ cells. Delayed senescence is seen in upfΔ cells lacking th...

  11. T-cell effector function and unresponsiveness in the murine lymphocytic choriomeningitis virus infection. I. On the mechanism of a selective suppression of the virus-specific delayed-type hypersensitivity response

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup

    1986-01-01

    pretreated with neutralizing anti-LCMV serum, indicating a suppressive effect of virus transferred with the infected cells. When tolerance induction was attempted with virus alone, a potentially fatal immune reaction could be altered to unresponsiveness (i.e. survival) as late as 4 days after an otherwise......-cell response remains essentially unchanged. When low-dose spleen effectors were transferred intravenously into intracerebrally infected high-dose mice, fatal LCM disease occurred, which means that infected central nervous system target structures in these animals are sensitive to virus-specific T cells. When...

  12. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  13. What are Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ahmadshah Farhat

    2014-05-01

    Full Text Available   Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem cells are those that can only form specific cells in the body such as blood cells based. Based on the sources of stem cells we have three types of these cells: Autologous: Sources of the patient own cells are (Autologous either the cells from patient own body or his or her cord blood. For this type of transplant the physician now usually collects the periphery rather than morrow because the procedure is easier on like a bane morrow harvest it take place outside of an operating room, and the patient does not to be under general unsetting . Allogenic: Sources of stem cells from another donore are primarily relatives (familial allogenic or completely unrelated donors. Xenogenic: In these stem cells from different species are transplanted e .g striatal porcine fetal mesan cephalic (FVM xenotransplants for Parkinson’s disease. On sites of isolation such as embryo, umbilical cord and other body tissues stem cells are named embnyonic, cord blood, and adult stem cells. The scope of results and clinical application of stem cells are such as: Neurodegenerative conditions (MS,ALS, Parkinson’s, Stroke, Ocular disorders- Glaucoma, retinitis Pigmentosa (RP, Auto Immune Conditions (Lupus, MS,R. arthritis, Diabetes, etc, Viral Conditions (Hepatitis C and AIDS, Heart Disease, Adrenal Disorders, Injury(Nerve, Brain, etc, Anti aging (hair, skin, weight control, overall well being/preventive, Emotional disorders, Organ / Tissue Cancers, Blood cancers, Blood diseases

  14. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  15. Stem cells in urology.

    Science.gov (United States)

    Aboushwareb, Tamer; Atala, Anthony

    2008-11-01

    The shortage of donors for organ transplantation has stimulated research on stem cells as a potential resource for cell-based therapy in all human tissues. Stem cells have been used for regenerative medicine applications in many organ systems, including the genitourinary system. The potential applications for stem cell therapy have, however, been restricted by the ethical issues associated with embryonic stem cell research. Instead, scientists have explored other cell sources, including progenitor and stem cells derived from adult tissues and stem cells derived from the amniotic fluid and placenta. In addition, novel techniques for generating stem cells in the laboratory are being developed. These techniques include somatic cell nuclear transfer, in which the nucleus of an adult somatic cell is placed into an oocyte, and reprogramming of adult cells to induce stem-cell-like behavior. Such techniques are now being used in tissue engineering applications, and some of the most successful experiments have been in the field of urology. Techniques to regenerate bladder tissue have reached the clinic, and exciting progress is being made in other areas, such as regeneration of the kidney and urethra. Cell therapy as a treatment for incontinence and infertility might soon become a reality. Physicians should be optimistic that regenerative medicine and tissue engineering will one day provide mainstream treatment options for urologic disorders.

  16. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    Directory of Open Access Journals (Sweden)

    Quanwen Liu

    2016-01-01

    Full Text Available In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment.

  17. Pluripotent Stem Cells for Schwann Cell Engineering

    NARCIS (Netherlands)

    Ma, Ming-San; Boddeke, Erik; Copray, Sjef

    2015-01-01

    Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitu

  18. Assessment of pancreas cells

    Science.gov (United States)

    Vanoss, C. J.

    1978-01-01

    Pancreatic islets were obtained from guinea pig pancreas by the collagenase method and kept alive in tissue culture prior to further studies. Pancreas cell morphology was studied by standard histochemical techniques using light microscopy. Preparative vertical electrophoresis-levitation of dispersed fetal guinea pig pancreas cells was conducted in phosphate buffer containing a heavy water (D20) gradient which does not cause clumping of cells or alter the osmolarity of the buffers. The faster migrating fractions tended to be enriched in beta-cell content. Alpha and delta cells were found to some degree in most fractions. A histogram showing the cell count distribution is included.

  19. Resident Peritoneal NK cells

    OpenAIRE

    Gonzaga, Rosemary; Matzinger, Polly; Perez-Diez, Ainhoa

    2011-01-01

    Here we describe a new population of NK cells that reside in the normal, un-inflamed peritoneal cavity. Phenotypically, they share some similarities with the small population of CD49b negative, CD27 positive immature splenic NK cells, and liver NK cells but differ in their expression of CD62L, TRAIL and EOMES. Functionally, the peritoneal NK cells resemble the immature splenic NK cells in their production of IFN-γ, GM-CSF and TNF-α and in the killing of YAC-1 target cells. We also found that ...

  20. Multipotent adult progenitor cell and stem cell plasticity

    OpenAIRE

    Jahagirdar, Balkrishna N; Verfaillie, Catherine

    2005-01-01

    Stem cells are defined by their biological function. A stem cell is an undifferentiated cell that self-renews to maintain the stem cell pool and at the single-cell level differentiates into more than one mature, functional cell. In addition, when transplanted, a stem cell should be capable of replacing a damaged organ or tissue for the lifetime of the recipient. Some would argue that stem cells should also be capable of functionally integrating into nondamaged tissues. Stem cells are critical...

  1. Epidermal Stem Cells

    Directory of Open Access Journals (Sweden)

    Osman Köse

    2015-03-01

    Full Text Available The epidermis is the outermost layer of the human skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. There are many origins of stem cells in the skin and skin appendages. These stem cells are localized in different part of the pilosebaseous units and also express many different genes. Epidermal stem cells in the pilosebaseous units not only ensure the maintenance of epidermal homeostasis and hair regeneration, but also contribute to repair of the epidermis after injury. In recent years, human induced pluripotent skin stem cells are produced from the epidermal cells such as keratinocytes, fibroblasts and melanocytes. These cells can be transdifferentiated to embriyonic stem cells. Human induced pluripotent stem cells have potential applications in cell replacement therapy and regenerative medicine. These cells provide a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. In this review, we aimed an overview of epidermal stem cells for better understanding their functions in the skin. Skin will be main organ for using the epidermal cells for regenerative medicine in near future.

  2. Stem Cell-Based Cell Therapy for Glomerulonephritis

    Directory of Open Access Journals (Sweden)

    Meiling Jin

    2014-01-01

    Full Text Available Glomerulonephritis (GN, characterized by immune-mediated inflammatory changes in the glomerular, is a common cause of end stage renal disease. Therapeutic options for glomerulonephritis applicable to all cases mainly include symptomatic treatment and strategies to delay progression. In the attempt to yield innovative interventions fostering the limited capability of regeneration of renal tissue after injury and the uncontrolled pathological process by current treatments, stem cell-based therapy has emerged as novel therapy for its ability to inhibit inflammation and promote regeneration. Many basic and clinical studies have been performed that support the ability of various stem cell populations to ameliorate glomerular injury and improve renal function. However, there is a long way before putting stem cell-based therapy into clinical practice. In the present article, we aim to review works performed with respect to the use of stem cell of different origins in GN, and to discuss the potential mechanism of therapeutic effect and the challenges for clinical application of stem cells.

  3. The cell cycle as a brake for β-cell regeneration from embryonic stem cells.

    Science.gov (United States)

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-13

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.

  4. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  5. Live-cell imaging study of mitochondrial morphology in mammalian cells exposed to X-rays

    International Nuclear Information System (INIS)

    Morphological changes in mitochondria induced by X-irradiation in normal murine mammary gland cells were studied with a live-cell microscopic imaging technique. Mitochondria were visualised by staining with a specific fluorescent probe in the cells, which express fluorescent ubiquitination-based cell-cycle indicator 2 (Fucci2) probes to visualise cell cycle. In unirradiated cells, the number of cells with fragmented mitochondria was about 20 % of the total cells through observation period (96 h). In irradiated cells, the population with fragmented mitochondria significantly increased depending on the absorbed dose. Particularly, for 8 Gy irradiation, the accumulation of fragmentation persists even in the cells whose cell cycle came to a stand (80 % in G1 (G0-like) phase). The fraction reached to a maximum at 96 h after irradiation. The kinetics of the fraction with fragmented mitochondria was similar to that for cells in S/G2/M phase (20 %) through the observation period (120 h). The evidences show that, in irradiated cells, some signals are continually released from a nucleus or cytoplasm even in the G0-like cells to operate some sort of protein machineries involved in mitochondrial fission. It is inferred that this delayed mitochondrial fragmentation is strongly related to their dysfunction, and hence might modulate radiobiological effects such as mutation or cell death. (authors)

  6. Live-cell imaging study of mitochondrial morphology in mammalian cells exposed to X-rays.

    Science.gov (United States)

    Noguchi, M; Kanari, Y; Yokoya, A; Narita, A; Fujii, K

    2015-09-01

    Morphological changes in mitochondria induced by X-irradiation in normal murine mammary gland cells were studied with a live-cell microscopic imaging technique. Mitochondria were visualised by staining with a specific fluorescent probe in the cells, which express fluorescent ubiquitination-based cell-cycle indicator 2 (Fucci2) probes to visualise cell cycle. In unirradiated cells, the number of cells with fragmented mitochondria was about 20 % of the total cells through observation period (96 h). In irradiated cells, the population with fragmented mitochondria significantly increased depending on the absorbed dose. Particularly, for 8 Gy irradiation, the accumulation of fragmentation persists even in the cells whose cell cycle came to a stand (80 % in G1 (G0-like) phase). The fraction reached to a maximum at 96 h after irradiation. The kinetics of the fraction with fragmented mitochondria was similar to that for cells in S/G2/M phase (20 %) through the observation period (120 h). The evidences show that, in irradiated cells, some signals are continually released from a nucleus or cytoplasm even in the G0-like cells to operate some sort of protein machineries involved in mitochondrial fission. It is inferred that this delayed mitochondrial fragmentation is strongly related to their dysfunction, and hence might modulate radiobiological effects such as mutation or cell death.

  7. Human neutrophils facilitate tumor cell transendothelial migration.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

  8. Mechanical communication in cardiac cell synchronized beating

    Science.gov (United States)

    Nitsan, Ido; Drori, Stavit; Lewis, Yair E.; Cohen, Shlomi; Tzlil, Shelly

    2016-05-01

    Cell-cell communication, which enables cells to coordinate their activity and is essential for growth, development and function, is usually ascribed a chemical or electrical origin. However, cells can exert forces and respond to environment elasticity and to mechanical deformations created by their neighbours. The extent to which this mechanosensing ability facilitates intercellular communication remains unclear. Here we demonstrate mechanical communication between cells directly for the first time, providing evidence for a long-range interaction that induces long-lasting alterations in interacting cells. We show that an isolated cardiac cell can be trained to beat at a given frequency by mechanically stimulating the underlying substrate. Deformations are induced using an oscillatory mechanical probe that mimics the deformations generated by a beating neighbouring cardiac cell. Unlike electrical field stimulation, the probe-induced beating rate is maintained by the cell for an hour after the stimulation stops, implying that long-term modifications occur within the cell. These long-term alterations provide a mechanism for cells that communicate mechanically to be less variable in their electromechanical delay. Mechanical coupling between cells therefore ensures that the final outcome of action potential pacing is synchronized beating. We further show that the contractile machinery is essential for mechanical communication.

  9. Toward 'SMART' stem cells.

    Science.gov (United States)

    Cheng, T

    2008-01-01

    Stem cell research is at the heart of regenerative medicine, which holds great promise for the treatment of many devastating disorders. However, in addition to hurdles posed by well-publicized ethical issues, this emerging field presents many biological challenges. What is a stem cell? How are embryonic stem cells different from adult stem cells? What are the physiological bases for therapeutically acceptable stem cells? In this editorial review, I will briefly discuss these superficially simple but actually rather complex issues that surround this fascinating cell type. The goal of this special issue on stem cells in Gene Therapy is to review some fundamental and critical aspects of current stem cell research that have translational potential. PMID:18046429

  10. Cell signaling review series

    Institute of Scientific and Technical Information of China (English)

    Aiming Lin; Zhenggang Liu

    2008-01-01

    @@ Signal transduction is pivotal for many, if not all, fundamental cellular functions including proliferation, differentiation, transformation and programmed cell death. Deregulation of cell signaling may result in certain types of cancers and other human diseases.

  11. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  12. Sickle cell anemia.

    OpenAIRE

    ŘÍHOVÁ, Tereza

    2013-01-01

    This thesis is about the disease called sickle cell anemia, or drepanocytosis. In this thesis is described the history of the disease, pathophysiology, laboratory features, various clinical features, diferencial diagnosis, quality of life in sickle cell anemia and therapy.

  13. Sickle Cell Trait

    Science.gov (United States)

    ... About Us Information For... Media Policy Makers Sickle Cell Trait Language: English Español (Spanish) Recommend on Facebook ... the trait on to their children. How Sickle Cell Trait is Inherited If both parents have SCT, ...

  14. Sickle Cell Disease Quiz

    Science.gov (United States)

    ... About Us Information For... Media Policy Makers Sickle Cell Disease Quiz Language: English Español (Spanish) Recommend on ... True or False: Only African Americans get sickle cell disease. A True B False 2. True or ...

  15. Mammalian cell biology

    International Nuclear Information System (INIS)

    This section contains summaries of research on mechanisms of lethality and radioinduced changes in mammalian cell properties, new cell systems for the study of the biology of mutation and neoplastic transformation, and comparative properties of ionizing radiations

  16. Anaplastic Large Cell Lymphoma

    Science.gov (United States)

    Anaplastic Large Cell Lymphoma Overview Lymphoma is the most common blood cancer. The two main forms of lymphoma are ... organs, and can accumulate to form tumors. Anaplastic large cell lymphoma (ALCL) is arare type of NHL, ...

  17. What Are Islet Cells?

    Science.gov (United States)

    ... Video Be Part of the Cure Commitment to Stem Cell Research Exercise + Drug Therapy Tibi Creates Garment to Benefit ... Video Be Part of the Cure Commitment to Stem Cell Research Exercise + Drug Therapy Tibi Creates Garment to Benefit ...

  18. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  19. Sickle cell anemia

    Science.gov (United States)

    ... for avascular necrosis of the hip Surgery for eye problems Treatment for overuse or abuse of narcotic pain medicines Wound care for leg ulcers Bone marrow or stem cell transplants can cure sickle cell anemia, but this treatment ...

  20. Diagram of Cell to Cell Communication

    Science.gov (United States)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  1. STEM CELLS AND PROTEOMICS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yong-ming; GUO Tian-nan; HUANG Shi-ang

    2006-01-01

    The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.

  2. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  3. Skeletal (stromal) stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Kermani, Abbas Jafari; Zaher, Walid;

    2015-01-01

    Skeletal (marrow stromal) stem cells (BMSCs) are a group of multipotent cells that reside in the bone marrow stroma and can differentiate into osteoblasts, chondrocytes and adipocytes. Studying signaling pathways that regulate BMSC differentiation into osteoblastic cells is a strategy....../preadipocyte factor 1 (Dlk1/Pref-1), the Wnt co-receptor Lrp5 and intracellular kinases. This article is part of a Special Issue entitled: Stem Cells and Bone....

  4. Nanoelectrochemistry of mammalian cells

    OpenAIRE

    Sun, Peng; Laforge, François O.; Abeyweera, Thushara P.; Rotenberg, Susan A.; Carpino, James; Mirkin, Michael V.

    2008-01-01

    There is a significant current interest in development of new techniques for direct characterization of the intracellular redox state and high-resolution imaging of living cells. We used nanometer-sized amperometric probes in combination with the scanning electrochemical microscope (SECM) to carry out spatially resolved electrochemical experiments in cultured human breast cells. With the tip radius ≈1,000 times smaller than that of a cell, an electrochemical probe can penetrate a cell and tra...

  5. Optimizing stem cell culture.

    OpenAIRE

    van der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

    2010-01-01

    International audience Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. In the past few years, major efforts have been made to define more precisely the medium composition in which stem cells grow or differentiate. This led to the progressive replacement of ill-defined additives such a...

  6. Fish stem cell cultures.

    Science.gov (United States)

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  7. Prostate cancer stem cells

    OpenAIRE

    Tu, Shi-Ming; Lin, Sue-Hwa

    2011-01-01

    Stem cells have long been implicated in prostate glandular formation. The prostate undergoes regression after androgen deprivation and regeneration after testosterone replacement. Regenerative studies suggest that these cells are found in the proximal ducts and basal layer of the prostate. Many characteristics of prostate cancer indicate that it originates from stem cells. For example, the putative AR− status of prostate stem cells renders them inherently insensitive to androgen blockade ther...

  8. Lung Cancer Stem Cells

    OpenAIRE

    Pine, Sharon R.; Blair Marshall; Lyuba Varticovski

    2008-01-01

    Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation p...

  9. Increased voltage photovoltaic cell

    Science.gov (United States)

    Ross, B.; Bickler, D. B.; Gallagher, B. D. (Inventor)

    1985-01-01

    A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

  10. Aneuploidy in stem cells

    OpenAIRE

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to reality. However, as somatic cells might have accumulated various chromosomal abnormalities, including aneuploidies throughout their lives, the resulting IPSCs might no longer carry the perfect bluepri...

  11. Antitumor Immunity Produced by the Liver Kupffer Cells, NK Cells, NKT Cells, and CD8+ CD122+ T Cells

    OpenAIRE

    Shuhji Seki; Hiroyuki Nakashima; Masahiro Nakashima; Manabu Kinoshita

    2011-01-01

    Mouse and human livers contain innate immune leukocytes, NK cells, NKT cells, and macrophage-lineage Kupffer cells. Various bacterial components, including Toll-like receptor (TLR) ligands and an NKT cell ligand ( α -galactocylceramide), activate liver Kupffer cells, which produce IL-1, IL-6, IL-12, and TNF. IL-12 activates hepatic NK cells and NKT cells to produce IFN- γ , which further activates hepatic T cells, in turn activating phagocytosis and cytokine production by Kupffer cells in a p...

  12. Erythropoietin signaling promotes transplanted progenitor cell survival

    OpenAIRE

    Jia, Yi; Warin, Renaud; Yu, Xiaobing; Epstein, Reed; Noguchi, Constance Tom

    2009-01-01

    We examine the potential for erythropoietin signaling to promote donor cell survival in a model of myoblast transplantation. Expression of a truncated erythropoietin receptor in hematopoietic stem cells has been shown to promote selective engraftment in mice. We previously demonstrated expression of endogenous erythropoietin receptor on murine myoblasts, and erythropoietin treatment can stimulate myoblast proliferation and delay differentiation. Here, we report that enhanced erythropoietin re...

  13. Nanostructured Organic Solar Cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Rubahn, Horst-Günter; Madsen, Morten

    Recent forecasts for alternative energy generation predict emerging importance of supporting state of art photovoltaic solar cells with their organic equivalents. Despite their significantly lower efficiency, number of application niches are suitable for organic solar cells. This work reveals...... the principles of bulk heterojunction organic solar cells fabrication as well as summarises major differences in physics of their operation....

  14. Stem cell heterogeneity revealed

    DEFF Research Database (Denmark)

    Andersen, Marianne S; Jensen, Kim B

    2016-01-01

    The skin forms a protective, water-impermeable barrier consisting of heavily crosslinked epithelial cells. However, the specific role of stem cells in sustaining this barrier remains a contentious issue. A detailed analysis of the interfollicular epidermis now proposes a model for how a composite...... of cells with different properties are involved in its maintenance....

  15. Aneuploidy in stem cells

    NARCIS (Netherlands)

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to real

  16. Cell phones and cancer

    Science.gov (United States)

    Cancer and cell phones; Do cell phones cause cancer? ... Several major studies show no link between cell phones and cancer at this time. However, since the information available is based on short-term studies, the impact of many years of ...

  17. Mouse Leydig Tumor Cells

    Directory of Open Access Journals (Sweden)

    Bo-Syong Pan

    2011-01-01

    Full Text Available Cordycepin is a natural pure compound extracted from Cordyceps sinensis (CS. We have demonstrated that CS stimulates steroidogenesis in primary mouse Leydig cell and activates apoptosis in MA-10 mouse Leydig tumor cells. It is highly possible that cordycepin is the main component in CS modulating Leydig cell functions. Thus, our aim was to investigate the steroidogenic and apoptotic effects with potential mechanism of cordycepin on MA-10 mouse Leydig tumor cells. Results showed that cordycepin significantly stimulated progesterone production in dose- and time-dependent manners. Adenosine receptor (AR subtype agonists were further used to treat MA-10 cells, showing that A1, A 2A , A 2B , and A3, AR agonists could stimulate progesterone production. However, StAR promoter activity and protein expression remained of no difference among all cordycepin treatments, suggesting that cordycepin might activate AR, but not stimulated StAR protein to regulate MA-10 cell steroidogenesis. Meanwhile, cordycepin could also induce apoptotic cell death in MA-10 cells. Moreover, four AR subtype agonists induced cell death in a dose-dependent manner, and four AR subtype antagonists could all rescue cell death under cordycepin treatment in MA-10 cells. In conclusion, cordycepin could activate adenosine subtype receptors and simultaneously induce steroidogenesis and apoptosis in MA-10 mouse Leydig tumor cells.

  18. Adventures with Cell Phones

    Science.gov (United States)

    Kolb, Liz

    2011-01-01

    Teachers are finding creative ways to turn the basic cell phone from a digital distraction into a versatile learning tool. In this article, the author explains why cell phones are important in learning and suggests rather than banning them that they be integrated into learning. She presents activities that can be done on a basic cell phone with a…

  19. Dazlin' pluripotent stem cells

    NARCIS (Netherlands)

    Welling, M.A.

    2014-01-01

    Pluripotent embryonic stem cells (ESCs) can be isolated from the inner cell mass (ICM) of blastocyst embryos and differentiate into all three germ layers in vitro. However, despite their similar origin, mouse embryonic stem cells represent a more naïve ICM-like pluripotent state whereas human embryo

  20. Embryonic Stem Cell Markers

    Directory of Open Access Journals (Sweden)

    Lan Ma

    2012-05-01

    Full Text Available Embryonic stem cell (ESC markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM technique and magnetic cell sorting (MACS are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs, which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells.

  1. astrocyte and astrocytoma cells

    DEFF Research Database (Denmark)

    Tfelt-Hansen, J.

    2008-01-01

    -transforming gene (PTTG), was found to be upregulated by the CaR in the H-500 cells, whereas calcium had no effect on PTTG expression in the U-87 astrocytoma cell line, but other proproliferative agents did upregulate PTTG in the U-87 cells. This makes PTTG a potential marker of malignancy and a therapeutic target...

  2. Advanced Cell Technology, Inc.

    Science.gov (United States)

    Caldwell, William M

    2007-03-01

    Advanced Cell Technology, Inc. (OTCBB: ACTC) is a biotechnology company applying novel human embryonic stem cell technologies in the emerging field of regenerative medicine. We believe that regenerative medicine has the potential to revolutionize the field by enabling scientists to produce human cells of any kind for use in a wide array of therapies.

  3. Battery cell module

    Energy Technology Data Exchange (ETDEWEB)

    Shambaugh, J.S.

    1981-11-23

    A modular lithium battery having a plurality of cells, having electrical connecting means connecting the cells to output terminals, and venting means for releasing discharge byproducts to a chemical scrubber is disclosed. Stainless steel cell casings are potted in an aluminum modular case with syntactic foam and epoxy. The wall thickness resulting is about 0.5 inches.

  4. Solar Photovoltaic Cells.

    Science.gov (United States)

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  5. High glucose suppresses embryonic stem cell differentiation into neural lineage cells.

    Science.gov (United States)

    Yang, Penghua; Shen, Wei-bin; Reece, E Albert; Chen, Xi; Yang, Peixin

    2016-04-01

    Abnormal neurogenesis occurs during embryonic development in human diabetic pregnancies and in animal models of diabetic embryopathy. Our previous studies in a mouse model of diabetic embryopathy have implicated that high glucose of maternal diabetes delays neurogenesis in the developing neuroepithelium leading to neural tube defects. However, the underlying process in high glucose-impaired neurogenesis is uncharacterized. Neurogenesis from embryonic stem (ES) cells provides a valuable model for understanding the abnormal neural lineage development under high glucose conditions. ES cells are commonly generated and maintained in high glucose (approximately 25 mM glucose). Here, the mouse ES cell line, E14, was gradually adapted to and maintained in low glucose (5 mM), and became a glucose responsive E14 (GR-E14) line. High glucose induced the endoplasmic reticulum stress marker, CHOP, in GR-E14 cells. Under low glucose conditions, the GR-E14 cells retained their pluripotency and capability to differentiate into neural lineage cells. GR-E14 cell differentiation into neural stem cells (Sox1 and nestin positive cells) was inhibited by high glucose. Neuron (Tuj1 positive cells) and glia (GFAP positive cells) differentiation from GR-E14 cells was also suppressed by high glucose. In addition, high glucose delayed GR-E14 differentiation into neural crest cells by decreasing neural crest markers, paired box 3 (Pax3) and paired box 7 (Pax7). Thus, high glucose impairs ES cell differentiation into neural lineage cells. The low glucose adapted and high glucose responsive GR-E14 cell line is a useful in vitro model for assessing the adverse effect of high glucose on the development of the central nervous system.

  6. Efficient Differentiation of Embryonic Stem Cells into Neurons in Glial Cell-conditioned Medium under Attaching Conditions

    Institute of Scientific and Technical Information of China (English)

    Hai-Bin TIAN; Zeng-Liang BAI; Hong WANG; Jian-Quan CHEN; Guo-Xiang CHENG

    2005-01-01

    Embryonic stem (ES) cells can differentiate into neurons in vitro, which provides hope for the treatment of some neurodegenerative diseases through cell transplantation. However, it remains a challenge to efficiently induce ES cells to differentiate into neurons. Here, we show that murine ES cells can efficiently differentiate into neurons when cultured in glial cell- conditioned medium (GCM) under attaching conditions without the formation of embryoid bodies. In comparison with murine embryonic fibroblast-conditioned medium, we found that GCM has a positive effect on limiting the generation of non-neuronal cells, such as astrocytes. In addition, compared with suspension conditions, attaching conditions delay the differentiation process of ES cells.

  7. 人参皂苷Rg1延缓造血干细胞衰老与p16INK4a表达关系的研究%Experimental study of relationship between effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence and expression of p16INK4a

    Institute of Scientific and Technical Information of China (English)

    周玥; 杨斌; 姚欣; 王亚平

    2011-01-01

    目的:探讨人参皂苷单体Rg1延缓造血干细胞(HSC)衰老与p16INK4a的表达调控关系,为寻找延缓HSC衰老途径提供理论和实验依据.方法:免疫磁性分选法分离纯化Sca-1+HSC后分组.对照组常规培养;衰老组运用三丁基过氧化氢(t-BHP)复制衰老模型;Rg1组在对照组基础上加入10μmol·L-1Rg1共培养;Rg1延缓衰老组给予10μmol·L-1Rg1预处理后,复制衰老模型;Rg1治疗衰老组,衰老模型复制后,给予10μmol·L-1Rg1抗衰老处理.衰老相关β半乳糖苷酶(SA-β-gal)细胞化学染色、流式细胞术分析细胞周期和造血祖细胞混合集落(CFU-Mix)培养确定Rg1延缓或治疗Sca-1+HSC衰老生物学作用.RT-PCR及Western blotting检测衰老相关基因pl6INK4amRNA及蛋白的表达.结果:Rg1延缓衰老组,Rg1治疗衰老组与衰老组相比,SA-β-gal染色阳性细胞百分比降低,G1期细胞比例下降,生成造血祖细胞混合集落数增加,p16INK4amRNA及蛋白的表达下降;Rg1延缓衰老组的SA-β-gal染色阳性细胞百分比、G1期比例、pl6INK4amRNA及蛋白的表达均低于Rg1治疗衰老组,形成造血祖细胞混合集落数高于Rg1治疗衰老组.结论:Rg1具有延缓和治疗Sca-1+HSC衰老的作用,Rg1延缓衰老比治疗衰老效果更好.Rg1可能通过调控p16INK4a的表达发挥其对抗t-BHP诱导的Sca-1+HSC衰老的作用.%Objective: To investigate the relation between the effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence and the expression of p16INK4a. The purpose is to provide the theory and experimental foundation for searching the methods of how to delay HSC senescence. Method: Sca-1 + HSC was isolated by magnetic cell sorting(MACS) and divided into five groups. The control group cells were routinely cultured, the aging group cells were induced aging by tert-butylhydroperoxide( t-BHP,final concentration of 100 μmol · L-1 ) to establish the aging model, the Rg1 group cells were co-cutured with Rg1 (final

  8. STEM CELLS: Differentiated cells in a back-up role

    OpenAIRE

    Desai, Tushar J.; Krasnow, Mark A.

    2013-01-01

    Two independent studies show that, if push comes to shove, differentiated cells of the stomach and lung can act as adult stem cells generating various cell types of the tissue, including a pool of stem cells.

  9. MAPK uncouples cell cycle progression from cell spreading and cytoskeletal organization in cycling cells

    OpenAIRE

    Margadant, Coert; Cremers, Lobke; Sonnenberg, Arnoud; Boonstra, Johannes

    2012-01-01

    Integrin-mediated cytoskeletal tension supports growth-factor-induced proliferation, and disruption of the actin cytoskeleton in growth factor-stimulated cells prevents the re-expression of cyclin D and cell cycle re-entry from quiescence. In contrast to cells that enter the cell cycle from G0, cycling cells continuously express cyclin D, and are subject to major cell shape changes during the cell cycle. Here, we investigated the cell cycle requirements for cytoskeletal tension and cell sprea...

  10. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    OpenAIRE

    Quanwen Liu; Yi Shen; Jiarong Chen; Jie Ding; Zihua Tang; Cui Zhang; Jianling Chen; Liang Li; Ping Chen; Jinfu Wang

    2016-01-01

    In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bund...

  11. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable...... scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  12. Transparent ultraviolet photovoltaic cells.

    Science.gov (United States)

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  13. Mechanics rules cell biology

    Directory of Open Access Journals (Sweden)

    Wang James HC

    2010-07-01

    Full Text Available Abstract Cells in the musculoskeletal system are subjected to various mechanical forces in vivo. Years of research have shown that these mechanical forces, including tension and compression, greatly influence various cellular functions such as gene expression, cell proliferation and differentiation, and secretion of matrix proteins. Cells also use mechanotransduction mechanisms to convert mechanical signals into a cascade of cellular and molecular events. This mini-review provides an overview of cell mechanobiology to highlight the notion that mechanics, mainly in the form of mechanical forces, dictates cell behaviors in terms of both cellular mechanobiological responses and mechanotransduction.

  14. Internalization of NK cells into tumor cells requires ezrin and leads to programmed cell-in-cell death

    Institute of Scientific and Technical Information of China (English)

    Shan Wang; Zhen Guo; Peng Xia; Tingting Liu; Jufang Wang; Shan Li; Lihua Sun; Jianxin Lu; Qian Wen; Mingqian Zhou; Li Ma; Xia Ding; Xiaoning Wang; Xuebiao Yao

    2009-01-01

    Cytotoxic lymphocytes are key players in the orchestration of immune response and elimination of defective cells. We have previously reported that natural killer (NK) cells enter target tumor cells, leading to either target cell death or self-destruction within tumor cells. However, it has remained elusive as to the fate of NK cells after internaliza-tion and whether the heterotypic cell-in-cell process is different from that of the homotypic cell-in-cell event recently named entosis. Here, we show that NK cells undergo a cell-in-cell process with the ultimate fate of apoptosis within tumor cells and reveal that the internalization process requires the actin cytoskeletal regulator, ezrin. To visualize how NK cells enter into tumor cells, we carried out real-time dual color imaging analyses of NK cell internalization into tumor cells. Surprisingly, most NK cells commit to programmed cell death after their entry into tumor cells, which is distinctively different from entosis observed in the homotypic cell-in-cell process. The apoptotic cell death of the internalized NK cells was evident by activation of caspase 3 and DNA fragmentation. Furthermore, NK cell death after internalization is attenuated by the caspase inhibitor, Z-VAD-FMK, confirming apoptosis as the mode of NK cell death within tumor cells. To determine protein factors essential for the entry of NK cells into tumor cells, we car-ried out siRNA-based knockdown analysis and discovered a critical role of ezrin in NK cell internalization. Impor-tantly, PKA-mediated phosphorylation of ezrin promotes the NK cell internalization process. Our findings suggest a novel regulatory mechanism by which ezrin governs NK cell internalization into tumor cells.

  15. Fuel Cell/Electrochemical Cell Voltage Monitor

    Science.gov (United States)

    Vasquez, Arturo

    2012-01-01

    A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

  16. Parameterization of solar cells

    Science.gov (United States)

    Appelbaum, J.; Chait, A.; Thompson, D.

    1992-10-01

    The aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current-voltage (I-V) characteristic curve. An alternative approach for cell performance prediction and cell screening is provided by modeling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I-V characteristic with seven parameters, by a double exponential model with five parameters, or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I-V characteristic, and introduce a procedure for screening of solar cells for arrays. We show that common curve fitting techniques, e.g., least squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I-V characteristics of the cell. Therefore, techniques relying on curve fitting criteria alone cannot be directly used for cell parameterization. We propose a consistent procedure which takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. The procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.

  17. T cell subpopulations.

    Science.gov (United States)

    Romagnani, Sergio

    2014-01-01

    The role of allergen-specific CD4+ effector type 2 helper (Th2) cells in the pathogenesis of allergic disorders is an established fact. Th2 cells produce interleukin (IL)-4 and IL-13, which induce immunoglobulin E production by B cells, and IL-5 that allows recruitment of eosinophils. Two main mechanisms control the Th2-mediated allergic inflammation: immune deviation (or Th1 redirection) and immune regulation. Regulatory T (Treg) cells exhibit a CD4+ phenotype and include Foxp3-positive thymic and induced Tregs, as well as Foxp3-negative IL-10-producing cells. Both immune deviation and immune regulation evoked by the maternal and newborn microbial environment probably operate in preventing allergen-specific Th2 responses. However, microbe-related protection from allergy seems to mainly depend on epigenetically controlled acetylation of the IFNG promoter of CD4+ T cells. Even Th17 and Th9 cells, as well as invariant NKT cells, have been implicated in the pathogenesis of allergic disorders, but their role is certainly more limited. Recently, innate lymphoid type 2 cells (ILC2) have been found to be able to produce high amounts of IL-5 and IL-13 in response to stimulation with IL-25 and IL-33 produced by non-immune cells. Together with Th2 cells, ILC2 may contribute to the induction and maintenance of allergic inflammation. PMID:24925396

  18. Cell adhesion in regulation of asymmetric stem cell division

    OpenAIRE

    Yamashita, Yukiko M

    2010-01-01

    Adult stem cells inevitably communicate with their cellular neighbors within the tissues they sustain. Indeed, such communication, particularly with components of the stem cell niche, is essential for many aspects of stem cell behavior, including the maintenance of stem cell identity and asymmetric cell division. Cell adhesion mediates this communication by placing stem cells in close proximity to the signaling source and by providing a polarity cue that orients stem cells. Here, I review the...

  19. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  20. Enteroendocrine cell types revisited

    DEFF Research Database (Denmark)

    Engelstoft, Maja S; Egerod, Kristoffer Lihme; Lund, Mari L;

    2013-01-01

    The GI-tract is profoundly involved in the control of metabolism through peptide hormones secreted from enteroendocrine cells scattered throughout the gut mucosa. A large number of recently generated transgenic reporter mice have allowed for direct characterization of biochemical and cell...... biological properties of these previously highly elusive enteroendocrine cells. In particular the surprisingly broad co-expression of six functionally related hormones in the intestinal enteroendocrine cells indicates that it should be possible to control not only the hormone secretion but also the type...... and number of enteroendocrine cells. However, this will require a more deep understanding of the factors controlling differentiation, gene expression and specification of the enteroendocrine cells during their weekly renewal from progenitor cells in the crypts of the mucosa....

  1. Mammary gland stem cells

    DEFF Research Database (Denmark)

    Fridriksdottir, Agla J R; Petersen, Ole W; Rønnov-Jessen, Lone

    2011-01-01

    Distinct subsets of cells, including cells with stem cell-like properties, have been proposed to exist in normal human breast epithelium and breast carcinomas. The cellular origins of epithelial cells contributing to gland development, tissue homeostasis and cancer are, however, still poorly...... understood. The mouse is a widely used model of mammary gland development, both directly by studying the mouse mammary epithelial cells themselves and indirectly, by studying development, morphogenesis, differentiation and carcinogenesis of xenotransplanted human breast epithelium in vivo. While in early...... studies, human or mouse epithelium was implanted as fragments into the mouse gland, more recent technical progress has allowed the self-renewal capacity and differentiation potential of distinct cell populations or even individual cells to be interrogated. Here, we review and discuss similarities...

  2. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  3. Peripheral giant cell granuloma

    Directory of Open Access Journals (Sweden)

    Padam Narayan Tandon

    2012-01-01

    Full Text Available Peripheral giant cell granuloma or the so-called "giant cell epulis" is the most common oral giant cell lesion. It normally presents as a soft tissue purplish-red nodule consisting of multinucleated giant cells in a background of mononuclear stromal cells and extravasated red blood cells. This lesion probably does not represent a true neoplasm, but rather may be reactive in nature, believed to be stimulated by local irritation or trauma, but the cause is not certainly known. This article reports a case of peripheral giant cell granuloma arising at the maxillary anterior region in a 22-year-old female patient. The lesion was completely excised to the periosteum level and there is no residual or recurrent swelling or bony defect apparent in the area of biopsy after a follow-up period of 6 months.

  4. T Cells Going Innate.

    Science.gov (United States)

    Seyda, Midas; Elkhal, Abdallah; Quante, Markus; Falk, Christine S; Tullius, Stefan G

    2016-08-01

    Natural killer (NK) cell receptors (NKRs) play a crucial role in the homeostasis of antigen-experienced T cells. Indeed, prolonged antigen stimulation may induce changes in the receptor repertoire of T cells to a profile that features NKRs. Chronic antigen exposure, at the same time, has been shown to trigger the loss of costimulatory CD28 molecules with recently reported intensified antigen thresholds of antigen-experienced CD8(+) T cells. In transplantation, NKRs have been shown to assist allograft rejection in a CD28-independent fashion. We discuss here a role for CD28-negative T cells that have acquired the competency of the NKR machinery, potentially promoting allorecognition either through T cell receptor (TCR) crossreactivity or independently from TCR recognition. Collectively, NKRs can bring about innate-like T cells by providing alternative costimulatory pathways that gain relevance in chronic inflammation, potentially leading to resistance to CD28-targeting immunosuppressants. PMID:27402226

  5. Effects of simulated microgravity on embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Yulan Wang

    Full Text Available There have been many studies on the biological effects of simulated microgravity (SMG on differentiated cells or adult stem cells. However, there has been no systematic study on the effects of SMG on embryonic stem (ES cells. In this study, we investigated various effects (including cell proliferation, cell cycle distribution, cell differentiation, cell adhesion, apoptosis, genomic integrity and DNA damage repair of SMG on mouse embryonic stem (mES cells. Mouse ES cells cultured under SMG condition had a significantly reduced total cell number compared with cells cultured under 1 g gravity (1G condition. However, there was no significant difference in cell cycle distribution between SMG and 1G culture conditions, indicating that cell proliferation was not impaired significantly by SMG and was not a major factor contributing to the total cell number reduction. In contrast, a lower adhesion rate cultured under SMG condition contributed to the lower cell number in SMG. Our results also revealed that SMG alone could not induce DNA damage in mES cells while it could affect the repair of radiation-induced DNA lesions of mES cells. Taken together, mES cells were sensitive to SMG and the major alterations in cellular events were cell number expansion, adhesion rate decrease, increased apoptosis and delayed DNA repair progression, which are distinct from the responses of other types of cells to SMG.

  6. Mast Cells Contribute to Peripheral Tolerance and Attenuate Autoimmune Vasculitis

    OpenAIRE

    Gan, Poh-Yi; Summers, Shaun A.; Ooi, Joshua D.; O’Sullivan, Kim M.; Tan, Diana S.Y.; Muljadi, Ruth C.M.; Odobasic, Dragana; Kitching, A. Richard; Holdsworth, Stephen R.

    2012-01-01

    Mast cells contribute to the modulation of the immune response, but their role in autoimmune renal disease is not well understood. Here, we induced autoimmunity resulting in focal necrotizing GN by immunizing wild-type or mast cell-deficient (KitW-sh/W-sh) mice with myeloperoxidase. Mast cell-deficient mice exhibited more antimyeloperoxidase CD4+ T cells, enhanced dermal delayed-type hypersensitivity responses to myeloperoxidase, and more severe focal necrotizing GN. Furthermore, the lymph no...

  7. Information on Stem Cell Research

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS Information on Stem Cell Research Research @ NINDS Stem Cell Highlights Submit a hESC ... found here: Human Induced Pluripotent Stem Cells NINDS Stem Cell Research on Campus The Intramural Research Program of NINDS ...

  8. Nevoid Basal Cell Carcinoma Syndrome

    Science.gov (United States)

    ... Nevoid Basal Cell Carcinoma Syndrome Request Permissions Nevoid Basal Cell Carcinoma Syndrome Approved by the Cancer.Net Editorial Board , 04/2016 What is Nevoid Basal Cell Carcinoma Syndrome? Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is ...

  9. PEROVSKITE SOLAR CELLS (REVIEW ARTICLE)

    OpenAIRE

    Benli, Deniz Ahmet

    2015-01-01

    A solar cell is a device that converts sunlight into electricity. There are different types of solar cells but this report mainly focuses on a type of new generation solar cell that has the name organo-metal halide perovskite, shortly perovskite solar cells. In this respect, the efficiency of power conversion is taken into account to replace the dominancy of traditional and second generation solar cell fields by perovskite solar cells. Perovskite solar cell is a type of solar cell including a...

  10. Introduction to Stem Cell Therapy

    OpenAIRE

    Biehl, Jesse K.; Russell, Brenda

    2009-01-01

    Stem cells have the ability to differentiate into specific cell types. The two defining characteristics of a stem cell are perpetual self-renewal and the ability to differentiate into a specialized adult cell type. There are two major classes of stem cells: pluripotent that can become any cell in the adult body, and multipotent that are restricted to becoming a more limited population of cells. Cell sources, characteristics, differentiation and therapeutic applications are discussed. Stem cel...

  11. Ki-67 is required for maintenance of cancer stem cells but not cell proliferation

    Science.gov (United States)

    Cidado, Justin; Wong, Hong Yuen; Rosen, D. Marc; Cimino-Mathews, Ashley; Garay, Joseph P.; Fessler, Abigail G.; Rasheed, Zeshaan A.; Hicks, Jessica; Cochran, Rory L.; Croessmann, Sarah; Zabransky, Daniel J.; Mohseni, Morassa; Beaver, Julia A.; Chu, David; Cravero, Karen; Christenson, Eric S.; Medford, Arielle; Mattox, Austin; De Marzo, Angelo M.; Argani, Pedram; Chawla, Ajay; Hurley, Paula J.; Lauring, Josh; Park, Ben Ho

    2016-01-01

    Ki-67 expression is correlated with cell proliferation and is a prognostic marker for various cancers; however, its function is unknown. Here we demonstrate that genetic disruption of Ki-67 in human epithelial breast and colon cancer cells depletes the cancer stem cell niche. Ki-67 null cells had a proliferative disadvantage compared to wildtype controls in colony formation assays and displayed increased sensitivity to various chemotherapies. Ki-67 null cancer cells showed decreased and delayed tumor formation in xenograft assays, which was associated with a reduction in cancer stem cell markers. Immunohistochemical analyses of human breast cancers revealed that Ki-67 expression is maintained at equivalent or greater levels in metastatic sites of disease compared to matched primary tumors, suggesting that maintenance of Ki-67 expression is associated with metastatic/clonogenic potential. These results elucidate Ki-67's role in maintaining the cancer stem cell niche, which has potential diagnostic and therapeutic implications for human malignancies. PMID:26823390

  12. Simple Cell Balance Circuit

    Science.gov (United States)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  13. Long-lived intestinal tuft cells serve as colon cancer–initiating cells

    Science.gov (United States)

    Westphalen, C. Benedikt; Asfaha, Samuel; Hayakawa, Yoku; Takemoto, Yoshihiro; Lukin, Dana J.; Nuber, Andreas H.; Brandtner, Anna; Setlik, Wanda; Remotti, Helen; Muley, Ashlesha; Chen, Xiaowei; May, Randal; Houchen, Courtney W.; Fox, James G.; Gershon, Michael D.; Quante, Michael; Wang, Timothy C.

    2014-01-01

    Doublecortin-like kinase 1 protein (DCLK1) is a gastrointestinal tuft cell marker that has been proposed to identify quiescent and tumor growth–sustaining stem cells. DCLK1+ tuft cells are increased in inflammation-induced carcinogenesis; however, the role of these cells within the gastrointestinal epithelium and their potential as cancer-initiating cells are poorly understood. Here, using a BAC-CreERT–dependent genetic lineage–tracing strategy, we determined that a subpopulation of DCLK1+ cells is extremely long lived and possesses rare stem cell abilities. Moreover, genetic ablation of Dclk1 revealed that DCLK1+ tuft cells contribute to recovery following intestinal and colonic injury. Surprisingly, conditional knockdown of the Wnt regulator APC in DCLK1+ cells was not sufficient to drive colonic carcinogenesis under normal conditions; however, dextran sodium sulfate–induced (DSS-induced) colitis promoted the development of poorly differentiated colonic adenocarcinoma in mice lacking APC in DCLK1+ cells. Importantly, colonic tumor formation occurred even when colitis onset was delayed for up to 3 months after induced APC loss in DCLK1+ cells. Thus, our data define an intestinal DCLK1+ tuft cell population that is long lived, quiescent, and important for intestinal homeostasis and regeneration. Long-lived DCLK1+ cells maintain quiescence even following oncogenic mutation, but are activated by tissue injury and can serve to initiate colon cancer. PMID:24487592

  14. Antitumor Cell-Complex Vaccines Employing Genetically Modified Tumor Cells and Fibroblasts

    Directory of Open Access Journals (Sweden)

    Antonio Miguel

    2014-02-01

    Full Text Available The present study evaluates the immune response mediated by vaccination with cell complexes composed of irradiated B16 tumor cells and mouse fibroblasts genetically modified to produce GM-CSF. The animals were vaccinated with free B16 cells or cell complexes. We employed two gene plasmid constructions: one high producer (pMok and a low producer (p2F. Tumor transplant was performed by injection of B16 tumor cells. Plasma levels of total IgG and its subtypes were measured by ELISA. Tumor volumes were measured and survival curves were obtained. The study resulted in a cell complex vaccine able to stimulate the immune system to produce specific anti-tumor membrane proteins (TMP IgG. In the groups vaccinated with cells transfected with the low producer plasmid, IgG production was higher when we used free B16 cell rather than cell complexes. Nonspecific autoimmune response caused by cell complex was not greater than that induced by the tumor cells alone. Groups vaccinated with B16 transfected with low producer plasmid reached a tumor growth delay of 92% (p ≤ 0.01. When vaccinated with cell complex, the best group was that transfected with high producer plasmid, reaching a tumor growth inhibition of 56% (p ≤ 0.05. Significant survival (40% was only observed in the groups vaccinated with free transfected B16 cells.

  15. B cells help alloreactive T cells differentiate into memory T cells1

    OpenAIRE

    Ng, Yue-Harn; Oberbarnscheidt, Martin H.; Chandramoorthy, Harish Chinna Konda; Hoffman, Rosemary; Chalasani, Geetha

    2010-01-01

    B cells are recognized as effector cells in allograft rejection that are dependent upon T cell help to produce alloantibodies causing graft injury. It is not known if B cells can also help T cells differentiate into memory cells in the alloimmune response. We found that in B cell-deficient hosts, differentiation of alloreactive T cells into effectors was intact whereas their development into memory T cells was impaired. To test if B cell help for T cells was required for their continued diffe...

  16. Mechanical plasticity of cells

    Science.gov (United States)

    Bonakdar, Navid; Gerum, Richard; Kuhn, Michael; Spörrer, Marina; Lippert, Anna; Schneider, Werner; Aifantis, Katerina E.; Fabry, Ben

    2016-10-01

    Under mechanical loading, most living cells show a viscoelastic deformation that follows a power law in time. After removal of the mechanical load, the cell shape recovers only incompletely to its original undeformed configuration. Here, we show that incomplete shape recovery is due to an additive plastic deformation that displays the same power-law dynamics as the fully reversible viscoelastic deformation response. Moreover, the plastic deformation is a constant fraction of the total cell deformation and originates from bond ruptures within the cytoskeleton. A simple extension of the prevailing viscoelastic power-law response theory with a plastic element correctly predicts the cell behaviour under cyclic loading. Our findings show that plastic energy dissipation during cell deformation is tightly linked to elastic cytoskeletal stresses, which suggests the existence of an adaptive mechanism that protects the cell against mechanical damage.

  17. Cytoskeleton and Cell Motility

    CERN Document Server

    Risler, Thomas

    2011-01-01

    The present article is an invited contribution to the Encyclopedia of Complexity and System Science, Robert A. Meyers Ed., Springer New York (2009). It is a review of the biophysical mechanisms that underly cell motility. It mainly focuses on the eukaryotic cytoskeleton and cell-motility mechanisms. Bacterial motility as well as the composition of the prokaryotic cytoskeleton is only briefly mentioned. The article is organized as follows. In Section III, I first present an overview of the diversity of cellular motility mechanisms, which might at first glance be categorized into two different types of behaviors, namely "swimming" and "crawling". Intracellular transport, mitosis - or cell division - as well as other extensions of cell motility that rely on the same essential machinery are briefly sketched. In Section IV, I introduce the molecular machinery that underlies cell motility - the cytoskeleton - as well as its interactions with the external environment of the cell and its main regulatory pathways. Sec...

  18. Induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Siddhartha Bhowmik; LI Yong

    2011-01-01

    Induced pluripotent stem (iPS) cells are a recent development which has brought a promise of great therapeutic values. The previous technique of somatic cell nuclear transfer (SCNT) has been ineffective in humans. Recent discoveries show that human fibroblasts can be reprogrammed by a transient over expression of a small number of genes; they can undergo induced pluripotency. iPS were first produced in 2006. By 2008, work was underway to remove the potential oncogenes from their structure. In 2009, protein iPS (piPS) cells were discovered. Surface markers and reporter genes play an important role in stem cell research. Clinical applications include generation of self renewing stem cells, tissue replacement and many more. Stem cell therapy has the ability to dramatically change the treatment of human diseases.

  19. NCAM regulates cell motility

    DEFF Research Database (Denmark)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna;

    2002-01-01

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells...... independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment...... to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine...

  20. Myoepithelial cells in pathology

    Directory of Open Access Journals (Sweden)

    N Balachander

    2015-01-01

    Full Text Available Myoepithelial cells are a normal constituent of the salivary acini and ducts and are found between the epithelial cells and the basement membrane. Microscopically myoepithelial cells are thin and spindle-shaped and ultrastructurally they possess a number of Cytoplasmic processes that extend between and over the acinar and ductal-lining cells, and they show features of both smooth muscle and epithelium. They play a vital role during expulsion of saliva and regulates the electrolytic exchange. They also perform as tumor suppressors and are considered to play a very important role in differentiation of various salivary gland tumors and help in the diagnosis of tumors. Neoplastic myoepithelial cells in both benign and malignant tumors can take numerous forms including epithelioid, plasmacytoid, spindle and clear cell variant, and this variability largely accounts for difficulties in histopathological diagnosis.

  1. Mammalian cell biology

    International Nuclear Information System (INIS)

    Studies of the action of N-ethylmaleimide (NEM), as an inhibitor of repair of x radioinduced injuries were extended from synchronous Chinese hamster cells to synchronous human HeLa cells. These studies showed a similar mode of action in both cell types lending support to the notion that conclusions may be extracted from such observations that are of fairly general applicability to mammalian cells. Radiation studies with NEM are being extended to hypoxic cells to inquire if NEM is effective relative to oxygen-independent damage. Observations relative to survival, DNA synthesis, and DNA strand elongation resulting from the addition products to DNA when cells were exposed to near uv in the presence of psoralen were extended. (U.S.)

  2. Fish germ cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.

  3. Basal cell carcinoma of the skin with areas of squamous cell carcinoma: a basosquamous cell carcinoma?

    OpenAIRE

    Faria, J.

    1985-01-01

    The diagnosis of basosquamous cell carcinoma is controversial. A review of cases of basal cell carcinoma showed 23 cases that had conspicuous areas of squamous cell carcinoma. This was distinguished from squamous differentiation and keratotic basal cell carcinoma by a comparative study of 40 cases of compact lobular and 40 cases of keratotic basal cell carcinoma. Areas of intermediate tumour differentiation between basal cell and squamous cell carcinoma were found. Basal cell carcinomas with ...

  4. Traction in smooth muscle cells varies with cell spreading

    Science.gov (United States)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  5. Quiescent cells: A natural way to resist chemotherapy

    Science.gov (United States)

    Menchón, S. A.; Condat, C. A.

    2011-10-01

    Most chemotherapeutic treatments use drugs that target proliferating cancer cells. Therefore, they do not affect quiescent cells which are naturally resistant. Surviving cancer cells can reactivate their cell cycles in the intervals between doses, becoming proliferative again and thus restarting tumor growth. In this work, we present a mathematical model to study the impact of quiescent cells on chemotherapy effectiveness. Our simulations show that, although tumor growth is delayed after the beginning of each dose, the resistance of quiescent cells is enough to reactivate it due to accelerated repopulation, eventually causing therapy failure even in the absence of acquired resistance.

  6. Microbial fuel cells

    International Nuclear Information System (INIS)

    Microbial fuel cells (MFC) are a promising technology for sustainable production of alternative energy and waste treatment. A microbial fuel cell transformation chemical energy in the chemical bonds in organic compounds to electrical energy through catalytic reactions of microorganisms under anaerobic conditions. It has been known for many years that it is possible to generate electricity directly by using bacteria to break down organic substrates. Key words: microbial fuel cells (MFC), biosensor, wastewater treatment

  7. Epidermal Stem Cells

    OpenAIRE

    Osman Köse

    2015-01-01

    The epidermis is the outermost layer of the human skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. There are many origins of stem cells in the skin and skin appendages. These stem cells are localized in different part of the pilosebaseous units and also express many different genes. Epidermal stem cells in the pilosebaseous units not only ensure the maintenance of epidermal homeostasis and ...

  8. Liver Cancer Stem Cells

    OpenAIRE

    Sameh Mikhail; Aiwu Ruth He

    2011-01-01

    Hepatocellular carcinoma is the most common primary malignancy of the liver in adults. It is also the fifth most common solid cancer worldwide and the third leading cause of cancer-related death. Recent research supports that liver cancer is a disease of adult stem cells. From the models of experimental hepatocarcinogenesis, there may be at least three distinct cell lineages with progenitor properties susceptible to neoplastic transformation. Identification of specific cell surface markers fo...

  9. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  10. Cell therapy of pseudarthrosis

    OpenAIRE

    Bastos Filho, Ricardo; Lermontov, Simone; Borojevic, Radovan; Schott, Paulo Cezar; Gameiro, Vinicius Schott; José Mauro GRANJEIRO

    2012-01-01

    Objective To assess the safety and efficiency of cell therapy for pseudarthrosis. Implant of the bone marrow aspirate was compared to mononuclear cells purified extemporaneously using the Sepax® equipment. Methods Six patients with nonunion of the tibia or femur were treated. Four received a percutaneous infusion of autologous bone marrow aspirated from the iliac crest, and two received autologous bone marrow mononuclear cells separated from the aspirate with the Sepax®. The primary fixation ...

  11. Chiaroscuro hematopoietic stem cell.

    OpenAIRE

    Quesenberry, P.; Habibian, M. (PhD); Dooner, M; Zhong, S.; Reilly, J; Peters, S.; De Becker, P; Grimaldi, C.; Carlson, J; REDDY, P; Nilsson, S.; Stewart, F. M.

    1998-01-01

    These observations suggest several immediate clinical strategies. In gene therapy, approaches could be targeted to obtain cycling of hematopoietic stem cells and gene-carrying retrovirus vector integration followed by engraftment at an appropriate time interval which favors engraftment. The same type of approach can be utilized for stem cell expansion approaches. Alternatively marrow or peripheral stem cell engraftment can be obtained with minimal to no toxicity in allochimeric strategies in ...

  12. Stem cell myths

    OpenAIRE

    Magnus, Tim; Liu, Ying; Parker, Graham C.; Rao, Mahendra S.

    2007-01-01

    Stem cells, although difficult to define, hold great promise as tools for understanding development and as therapeutic agents. However, as with any new field, uncritical enthusiasm can outstrip reality. In this review, we have listed nine common myths that we believe affect our approach to evaluating stem cells for therapy. We suggest that careful consideration needs to be given to each of these issues when evaluating a particular cell for its use in therapy. Data need to be collected and rep...

  13. Cancer stem cell metabolism

    OpenAIRE

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E.; Pestell, Richard G.; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    Cancer is now viewed as a stem cell disease. There is still no consensus on the metabolic characteristics of cancer stem cells, with several studies indicating that they are mainly glycolytic and others pointing instead to mitochondrial metabolism as their principal source of energy. Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes. Deter...

  14. Lung Stem cell biology

    OpenAIRE

    Ardhanareeswaran, Karthikeyan; Mirotsou, Maria

    2013-01-01

    Over the past few years new insights have been added to the study of stem cells in the adult lung. The exploration of the endogenous lung progenitors as well as the study of exogenously delivered stem cell populations holds promise for advancing our understanding of the biology of lung repair mechanisms. Moreover, it opens new possibilities for the use of stem cell therapy for the development of regenerative medicine approaches for the treatment of lung disease. Here, we discuss the main type...

  15. Gastric Cancer Stem Cells

    OpenAIRE

    Takaishi, Shigeo; Okumura, Tomoyuki; Timothy C Wang

    2008-01-01

    Cancer stem cells are defined as the unique subpopulation in the tumors that possess the ability to initiate tumor growth and sustain self-renewal as well as metastatic potential. Accumulating evidence in recent years strongly indicate the existence of cancer stem cells in solid tumors of a wide variety of organs. In this review, we will discuss the possible existence of a gastric cancer stem cell. Our recent data suggest that a subpopulation with a defined marker shows spheroid colony format...

  16. APUD cells in teratomas.

    OpenAIRE

    Bosman, F. T.; Louwerens, J. W.

    1981-01-01

    The origin of the endocrine cells in the respiratory tract and the gastrointestinal tract is still a matter of debate. In the original concept of the amine precursor uptake and decarboxylation (APUD) system, all APUD cells were considered to be derived from the neural crest. More recently it has been proposed that the APUD cell types of the gastrointestinal and respiratory tracts originate from neuroendocrine-programmed ectoblast. Still other investigators have reported observations that favo...

  17. Hair cell ribbon synapses

    OpenAIRE

    Moser, Tobias; Brandt, Andreas; Lysakowski, Anna

    2006-01-01

    Hearing and balance rely on the faithful synaptic coding of mechanical input by the auditory and vestibular hair cells of the inner ear. Mechanical deflection of their stereocilia causes the opening of mechanosensitive channels, resulting in hair cell depolarization, which controls the release of glutamate at ribbon-type synapses. Hair cells have a compact shape with strong polarity. Mechanoelectrical transduction and active membrane turnover associated with stereociliar renewal dominate the ...

  18. Systems cell biology.

    Science.gov (United States)

    Mast, Fred D; Ratushny, Alexander V; Aitchison, John D

    2014-09-15

    Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology.

  19. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ilan

    2006-12-15

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  20. Mesenchymal stem cells.

    Science.gov (United States)

    Ding, Dah-Ching; Shyu, Woei-Cherng; Lin, Shinn-Zong

    2011-01-01

    Stem cells have two features: the ability to differentiate along different lineages and the ability of self-renewal. Two major types of stem cells have been described, namely, embryonic stem cells and adult stem cells. Embryonic stem cells (ESC) are obtained from the inner cell mass of the blastocyst and are associated with tumorigenesis, and the use of human ESCs involves ethical and legal considerations. The use of adult mesenchymal stem cells is less problematic with regard to these issues. Mesenchymal stem cells (MSCs) are stromal cells that have the ability to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as umbilical cord, endometrial polyps, menses blood, bone marrow, adipose tissue, etc. This is because the ease of harvest and quantity obtained make these sources most practical for experimental and possible clinical applications. Recently, MSCs have been found in new sources, such as menstrual blood and endometrium. There are likely more sources of MSCs waiting to be discovered, and MSCs may be a good candidate for future experimental or clinical applications. One of the major challenges is to elucidate the mechanisms of differentiation, mobilization, and homing of MSCs, which are highly complex. The multipotent properties of MSCs make them an attractive choice for possible development of clinical applications. Future studies should explore the role of MSCs in differentiation, transplantation, and immune response in various diseases. PMID:21396235

  1. Red cell enzymes.

    Science.gov (United States)

    Paniker, N V

    1975-03-01

    As compared to other cells of the body, the mammalian red cell has one of the simplest structural organizations. As a result, this cell has been extensively used in studies involving the structure, function, and integrity of cell membranes as well as cytoplasmic events. Additionally, the metabolic activities of the red blood cell are also relatively simple. During the past quarter century or so, an ocean of knowledge has been gathered on various aspects of red cell metabolism and function. The fields of enzymes, hemoglobin, membrane, and metabolic products comprise the major portion of this knowledge. These advances have made valuable contributions to biochemistry and medicine. Despite these favorable aspects of this simple, anucleated cell, it must be conceded that our knowledge about the red cell is far from complete. We are still in the dark concerning the mechanism involved in several aspects of its membrane, hemoglobin, enzymes, and a large number of other constituents. For example, a large number of enzymes with known catalytic activity but with unknown function have eluded investigators despite active pursuit. This review will be a consolidation of our present knowledge of human red cell enzymes, with particular reference to their usefulness in the diagnosis and therapy of disease. Owing to the multitude of publications by prominent investigators on each of the approximately 50 enzymes discussed in this review, it was impossible to cite a majority of them.

  2. Littoral Cells 2005

    Data.gov (United States)

    California Department of Resources — Littoral cells along the California Coast. Originally digitized by Melanie Coyne from the Assessment and Atlas of Shoreline Erosion Along the California Coast...

  3. HTPEM Fuel Cell Impedance

    DEFF Research Database (Denmark)

    Vang, Jakob Rabjerg

    potentially play an important role in the energy system of the future. One of the fuel cell technologies, that receives much attention from the Danish scientific community is high temperature proton exchange membrane (HTPEM) fuel cells based on polybenzimidazole (PBI) with phosphoric acid as proton conductor...... cells through experimental studies and mathematical modelling. These studies all revolve around the electrochemical impedance spectroscopy (EIS) characterisation method. EIS is performed by applying a sinusoidal current or voltage signal to the fuel cell and calculating the impedance from the response...

  4. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  5. Multiple granular cell tumor.

    Science.gov (United States)

    Jones, J K; Kuo, T T; Griffiths, C M; Itharat, S

    1980-10-01

    Eleven cases of granular cell tumor were reviewed. In two of the cases multiple sites of involvement were seen. The tumor occurred in the oral cavity in both of these cases and each was initially wrongly diagnosed as squamous cell carcinoma. The most common site was the subcutaneous tissue (nine patients) and the tongue was involved in three cases. In one patient the parotid gland was involved. Eight of the patients were females and three were males; seven were black and four were white. The importance of differentiating between squamous cell carcinoma and granular cell tumor is stressed, as is the need for a simple wide surgical excision. PMID:7421377

  6. Live-cell luciferase assay of drug resistant cells

    OpenAIRE

    sprotocols

    2015-01-01

    To date, multiplexing cell-based assay is essential for high-throughput screening of molecular targets. Measuring multiple parameters of a single sample increases consistency and decrease time and cost of assay. Functional assay of living cell is useful as a first step of multiplexing assay, because live-cell assay allows following second assay using cell lysate or stained cell. However, live-cell assay of drug resistant cells that are highly activated of drug efflux mechanisms is sometimes u...

  7. [Dendritic cells and interaction with other cell types. Immune tolerance].

    Science.gov (United States)

    Guerder, S

    2001-07-01

    T cell tolerance to self antigen is mainly established in the thymus were self-reactive T cells are deleted. Interdigitating dendritic cells and medulary epithelial cells are directly involved in the deletion process. Some self-reactive T cells escape, however this thymic censorship and enter the peripheral pool of naive T cells. Multiple mechanisms are also at play in the periphery to control this potentially armfull T cells, this include deletion and immune deviation.

  8. A focus on parietal cells as a renewing cell population

    Institute of Scientific and Technical Information of China (English)

    Sherif; M; Karam

    2010-01-01

    The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells...

  9. Stem cells - biological update and cell therapy progress

    OpenAIRE

    GIRLOVANU, MIHAI; Susman, Sergiu; Soritau, Olga; RUS-CIUCA, DAN; MELINCOVICI, CARMEN; CONSTANTIN, ANNE-MARIE; Carmen Mihaela MIHU

    2015-01-01

    In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods t...

  10. Liver epithelial cells inhibit proliferation and invasiveness of hepatoma cells.

    Science.gov (United States)

    Jeng, Kuo-Shyang; Jeng, Chi-Juei; Jeng, Wen-Juei; Sheen, I-Shyan; Li, Shih-Yun; Hung, Zih-Hang; Hsiau, Hsin-I; Yu, Ming-Che; Chang, Chiung-Fang

    2016-03-01

    Hepatocellular carcinoma (HCC) is a worldwide malignancy with poor prognosis. Liver progenitors or stem cells could be a potential therapy for HCC treatment since they migrate toward tumors. Rat liver epithelial (RLE) cells have both progenitor and stem cell-like properties. Therefore, our study elucidated the therapeutic effect of RLE cells in rat hepatoma cells. RLE cells were isolated from 10-day old rats and characterized for stem cell marker expression. RLE cells and rat hepatoma cells (H4-IIE-C3 cells) were co-cultured and divided into four groups with different ratios of RLE and hepatoma cells. Group A had only rat hepatoma cells as a control group. The ratios of rat hepatoma and RLE cells in group B, C and D were 5:1, 1:1 and 1:5, respectively. Effective inhibition of cell proliferation and migration was found in group D when compared to group A. There was a significant decrease in Bcl2 expression and increase in late apoptosis of rat hepatoma cells when adding more RLE cells. RLE cells reduced cell proliferation and migration of rat hepatoma cells. These results suggested that RLE cells could be used as a potential cell therapy. PMID:26647726

  11. Effect of Lithium on Cell Cycle Progression of Pig Airway Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    陈文书; 吴人亮; 王曦; 李媛; 郝天玲

    2004-01-01

    To investigate the effect of lithium on cell cycle progression of airway epithelial cells,primary pig tracheobronchial epithelial cells were incubated with lithium chloride (LiCl) at different concentrations (0, 5 mmol/L, and 10 mmol/L) and time (12 h, 16 h and 24 h). After the treatment, cells were counted, cell cycle profile was measured by BrdU labeling and flow cytometry, and expression of cyclin D1 and cyclin B1 were detected by Western blotting. The results showed that after 24h of 10mmol/L but not 5mmol/L LiCl treatment, proliferation of cells was slowed down as manifested by delayed confluence and cell number accumulation (P<0.05). Lithium did not change the percentage of cells in S phase (P>0.05), but 24 h incubation with 10 mmol/L LiCl induced a G2/M cell cycle arrest. Furthermore, 10mmol/L LiCl elevated cyclin D1 expression after 12h treatment, while expression of cyclin B1 increased more significantly after 24h incubation. These data demonstrate that lithium inhibits proliferation of pig airway epithelial cells by inhibiting cell cycle progression, and suggest that lithium-sensitive molecule(s) such as glycogen synthase kinase 3 may have a role in the regulation of growth of airway epithelial cells.

  12. Polarised cells, polarised views: Asymmetric cell division in hematopoietic cells.

    Directory of Open Access Journals (Sweden)

    Kim ePham

    2014-02-01

    Full Text Available It has long been recognised that alterations in cell shape and polarity play important roles in coordinating lymphocyte functions. In the last decade a new aspect of lymphocyte polarity, termed Asymmetric Cell Division (ACD, has attracted much attention. ACD has previously been shown to dictate or influence many aspects of development in model organisms such as the worm and the fly, and to be disrupted in disease. Recent observations that ACD also occurs in lymphocytes led to exciting speculations that ACD might influence lymphocyte differentiation and function, and leukaemia. However, dissecting the role that ACD might play in these activities is not straightforward, and the evidence to date for a functional role in lymphocyte fate determination has been controversial. In this review, we discuss the evidence to date for ACD in lymphocytes, and how it might influence lymphocyte fate. We also discuss current gaps in our knowledge, and suggest approaches to definitively test the physiological role of ACD in lymphocytes.

  13. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  14. Wnt-Dependent Control of Cell Polarity in Cultured Cells.

    Science.gov (United States)

    Runkle, Kristin B; Witze, Eric S

    2016-01-01

    The secreted ligand Wnt5a regulates cell polarity and polarized cell movement during development by signaling through the poorly defined noncanonical Wnt pathway. Cell polarity regulates most aspects of cell behavior including the organization of apical/basolateral membrane domains of epithelial cells, polarized cell divisions along a directional plane, and front rear polarity during cell migration. These characteristics of cell polarity allow coordinated cell movements required for tissue formation and organogenesis during embryonic development. Genetic model organisms have been used to identify multiple signaling pathways including Wnt5a that are required to establish cell polarity and regulate polarized cell behavior. However, the downstream signaling events that regulate these complex cellular processes are still poorly understood. The methods below describe assays to study Wnt5a-induced cell polarity in cultured cells, which may facilitate our understanding of these complex signaling pathways. PMID:27590152

  15. The new stem cell biology.

    OpenAIRE

    Quesenberry, Peter J.; Colvin, Gerald A; Lambert, Jean-Francois; Frimberger, Angela E.; Dooner, Mark S.; Mcauliffe, Christina I.; Miller, Caroline; Becker, Pamela; Badiavas, Evangelis; Falanga, Vincent J.; Elfenbein, Gerald; Lum, Lawrence G.

    2002-01-01

    Recent studies have indicated that bone marrow stem cells are capable of generating muscle, cardiac, hepatic, renal, and bone cells. Purified hematopoietic stem cells have generated cardiac and hepatic cells and reversed disease manifestations in these tissues. Hematopoietic stem cells also alter phenotype with cell cycle transit or circadian phase. During a cytokine stimulated cell cycle transit, reversible alterations of differentiation and engraftment occur. Primitive hematopoietic stem ce...

  16. Small cell glioblastoma or small cell carcinoma

    DEFF Research Database (Denmark)

    Hilbrandt, Christine; Sathyadas, Sathya; Dahlrot, Rikke H;

    2013-01-01

    was admitted to the hospital with left-sided loss of motor function. A MRI revealed a 6 cm tumor in the right temporoparietal area. The histology was consistent with both glioblastoma multiforme (GBM) and small cell lung carcinoma (SCLC) but IHC was suggestive of a SCLC metastasis. PET-CT revealed...

  17. Tracking Down Mutations Cell by Cell.

    Science.gov (United States)

    Kosik, Kenneth S

    2016-03-16

    Using somatic cell nuclear transfer, Hazen et al. (2016) examined clonally expanded single neurons for mutations and found ∼100 mutations from a variety of classes. Post-mitotic mutations in individual neurons represent an exploratory direction for finding fundamental origins of neurodegeneration. PMID:26985720

  18. Brain repair: cell therapy in stroke

    Directory of Open Access Journals (Sweden)

    Kalladka D

    2014-02-01

    Full Text Available Dheeraj Kalladka, Keith W Muir Institute of Neuroscience and Psychology, University of Glasgow, Southern General Hospital, Glasgow, United Kingdom Abstract: Stroke affects one in every six people worldwide, and is the leading cause of adult disability. Some spontaneous recovery is usual but of limited extent, and the mechanisms of late recovery are not completely understood. Endogenous neurogenesis in humans is thought to contribute to repair, but its extent is unknown. Exogenous cell therapy is promising as a means of augmenting brain repair, with evidence in animal stroke models of cell migration, survival, and differentiation, enhanced endogenous angiogenesis and neurogenesis, immunomodulation, and the secretion of trophic factors by stem cells from a variety of sources, but the potential mechanisms of action are incompletely understood. In the animal models of stroke, both mesenchymal stem cells (MSCs and neural stem cells (NSCs improve functional recovery, and MSCs reduce the infarct volume when administered acutely, but the heterogeneity in the choice of assessment scales, publication bias, and the possible confounding effects of immunosuppressants make the comparison of effects across cell types difficult. The use of adult-derived cells avoids the ethical issues around embryonic cells but may have more restricted differentiation potential. The use of autologous cells avoids rejection risk, but the sources are restricted, and culture expansion may be necessary, delaying treatment. Allogeneic cells offer controlled cell numbers and immediate availability, which may have advantages for acute treatment. Early clinical trials of both NSCs and MSCs are ongoing, and clinical safety data are emerging from limited numbers of selected patients. Ongoing research to identify prognostic imaging markers may help to improve patient selection, and the novel imaging techniques may identify biomarkers of recovery and the mechanism of action for cell

  19. Transition of mesenchymal stem/stromal cells to endothelial cells

    NARCIS (Netherlands)

    M. Crisan (Mihaela)

    2013-01-01

    textabstractMesenchymal stem/stromal cells (MSCs) are heterogeneous. A fraction of these cells constitute multipotent cells that can self-renew and mainly give rise to mesodermal lineage cells such as adipocytes, osteocytes and chondrocytes. The ability of MSCs to differentiate into endothelial cell

  20. Induction of embryonic stem cells to hematopoietic cells in vitro

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to get hematopoietic cells from embryonic stem (ES) cells and to study development mechanisms of hematopoietic cells, the method of inducing embryonic stem cells to hematopoietic cells was explored by differenciating mouse ES cells and human embryonic cells in three stages. The differentiated cells were identified by flow cytometry, immunohistochemistry and Wright's staining. The results showed that embryoid bodies (EBs) could form when ES cells were cultured in the medium with 2-mercaptoethanol (2-ME). However, cytokines, such as stem cell factor (SCF), thrombopoietin (TPO), interleukin-3 (IL-3), interleukin-6 (IL-6), erythropoietin (EPO) and granular colony stimulating factor (G-CSF), were not helpful for forming EBs. SCF, TPO and embryonic cell conditional medium were useful for the differentiation of mouse EBs to hematopoietic progenitors. Eighty-six percent of these cells were CD34+ after 6-d culture. Hematopoietic progenitors differentiated to B lymphocytes when they were cocultured with primary bone marrow stroma cells in the DMEM medium with SCF and IL-6. 14 d later, most of the cells were CD34-CD38+. Wright's staining and immunohistochemistry showed that 80% of these cells were plasma-like morphologically and immunoglubolin positive. The study of hematopoietic cells from human embryonic cells showed that human embryonic cell differentiation was very similar to that of mouse ES cells. They could form EBs in the first stage and the CD34 positive cells account for about 48.5% in the second stage.

  1. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...

  2. Fuel cells: Operating flexibly

    Science.gov (United States)

    Lee, Young Moo

    2016-09-01

    Fuel cells typically function well only in rather limited temperature and humidity ranges. Now, a proton exchange membrane consisting of ion pair complexes is shown to enable improved fuel cell performance under a wide range of conditions that are unattainable with conventional approaches.

  3. The Constitution by Cell

    Science.gov (United States)

    Greenhut, Stephanie; Jones, Megan

    2010-01-01

    On their visit to the National Archives Experience in Washington, D.C., students in Jenni Ashley and Gay Brock's U.S. history classes at the Potomac School in McLean, Virginia, participated in a pilot program called "The Constitution by Cell." Armed with their cell phones, a basic understanding of the Constitution, and a willingness to participate…

  4. MICROBIAL FUEL CELL

    DEFF Research Database (Denmark)

    2008-01-01

    A novel microbial fuel cell construction for the generation of electrical energy. The microbial fuel cell comprises: (i) an anode electrode, (ii) a cathode chamber, said cathode chamber comprising an in let through which an influent enters the cathode chamber, an outlet through which an effluent...

  5. Cell Phones for Education

    Science.gov (United States)

    Roberson, James H.; Hagevik, Rita A.

    2008-01-01

    Cell phones are fast becoming an integral part of students' everyday lives. They are regarded as important companions and tools for personal expression. School-age children are integrating the cell phone as such, and thus placing a high value on them. Educators endeavor to instill in students a high value for education, but often meet with…

  6. Printed paper photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Huebler, Arved; Trnovec, Bystrik; Zillger, Tino; Ali, Moazzam; Wetzold, Nora [Inistitute for Print and Media Technology, Chemnitz University of Technology, Chemnitz (Germany); Mingebach, Markus; Wagenpfahl, Alexander; Deibel, Carsten [Experimental Physics VI, Julius-Maximilians-University of Wuerzburg (Germany); Dyakonov, Vladimir [Experimental Physics VI, Julius-Maximilians-University of Wuerzburg (Germany); Bavarian Center for Applied Energy Research e.V. (ZAE Bayern), Wuerzburg (Germany)

    2011-11-15

    Polymer/fullerene solar cells are printed on paper using a combination of gravure and flexographic printing techniques. The printed paper photovoltaic cells are free from expensive electrodes made with indium-tin oxide, silver, or gold. Oxidized zinc film is used as the electron-collecting layer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Ghrelin and cell differentiation

    Institute of Scientific and Technical Information of China (English)

    Geyang Xu; Yin Li; Wenjiao An; Weizhen Zhang

    2008-01-01

    Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is a gastric hormone that has been found to have a wide variety of biological functions. This review summarizes our current understanding of the effects of ghrelin on cell differentiation and tissue development, with an emphasis on the lineage determination of mesenchymal stem cells.

  8. Mesangial cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Abboud, Hanna E., E-mail: Abboud@uthscsa.edu

    2012-05-15

    Mesangial cells originate from the metanephric mesenchyme and maintain structural integrity of the glomerular microvascular bed and mesangial matrix homeostasis. In response to metabolic, immunologic or hemodynamic injury, these cells undergo apoptosis or acquire an activated phenotype and undergo hypertrophy, proliferation with excessive production of matrix proteins, growth factors, chemokines and cytokines. These soluble factors exert autocrine and paracrine effects on the cells or on other glomerular cells, respectively. MCs are primary targets of immune-mediated glomerular diseases such as IGA nephropathy or metabolic diseases such as diabetes. MCs may also respond to injury that primarily involves podocytes and endothelial cells or to structural and genetic abnormalities of the glomerular basement membrane. Signal transduction and oxidant stress pathways are activated in MCs and likely represent integrated input from multiple mediators. Such responses are convenient targets for therapeutic intervention. Studies in cultured MCs should be supplemented with in vivo studies as well as examination of freshly isolated cells from normal and diseases glomeruli. In addition to ex vivo morphologic studies in kidney cortex, cells should be studied in their natural environment, isolated glomeruli or even tissue slices. Identification of a specific marker of MCs should help genetic manipulation as well as selective therapeutic targeting of these cells. Identification of biological responses of MCs that are not mediated by the renin–angiotensin system should help development of novel and effective therapeutic strategies to treat diseases characterized by MC pathology.

  9. Stem cells in dermatology.

    Science.gov (United States)

    Ogliari, Karolyn Sassi; Marinowic, Daniel; Brum, Dario Eduardo; Loth, Fabrizio

    2014-01-01

    Preclinical and clinical research have shown that stem cell therapy could be a promising therapeutic option for many diseases in which current medical treatments do not achieve satisfying results or cure. This article describes stem cells sources and their therapeutic applications in dermatology today.

  10. T-cell costimulation

    DEFF Research Database (Denmark)

    Owens, T

    1996-01-01

    The CD40L molecule expressed by CD4+ regulatory T lymphocytes is known to deliver signals that activate B cells and macrophages. It now appears that CD40L regulates T cells themselves, during both their development and their participation in adaptive immune responses....

  11. Cell Maintenance Systems

    Science.gov (United States)

    Morrison, D. R.

    1985-01-01

    Living human cells require attachment to a suitable surface and special culture conditions in order to grow. These requirements are modified and amplified when cells are taken into a weightless environment. Special handling and maintenance systems are required for routine laboratory procedures conducted in the Orbiter and in the Spacelab. Methods were developed to maintain cells in special incubators designed for the Orbiter middeck, however, electrophoresis and other experiments require cells to be harvested off of the culture substrate before they can be processed or used. The cell transport assembly (CTA) was flown on STS-8, and results show that improvements are required to maintain adequate numbers of cells in this device longer than 48 hours. The life sciences middeck centrifuge probably can be used, but modifications will be required to transfer cells from the CTA and keep the cells sterile. Automated systems such as the Skylab SO-15 flight hardware and crew operated systems are being evaluated for use on the Space Shuttle, Spacelab, and Space Station research modules.

  12. Tumor cell metabolism

    Science.gov (United States)

    Romero-Garcia, Susana; Lopez-Gonzalez, Jose Sullivan; B´ez-Viveros, José Luis; Aguilar-Cazares, Dolores

    2011-01-01

    Cancer is a genetic disease that is caused by mutations in oncogenes, tumor suppressor genes and stability genes. The fact that the metabolism of tumor cells is altered has been known for many years. However, the mechanisms and consequences of metabolic reprogramming have just begun to be understood. In this review, an integral view of tumor cell metabolism is presented, showing how metabolic pathways are reprogrammed to satisfy tumor cell proliferation and survival requirements. In tumor cells, glycolysis is strongly enhanced to fulfill the high ATP demands of these cells; glucose carbons are the main building blocks in fatty acid and nucleotide biosynthesis. Glutaminolysis is also increased to satisfy NADPH regeneration, whereas glutamine carbons replenish the Krebs cycle, which produces metabolites that are constantly used for macromolecular biosynthesis. A characteristic feature of the tumor microenvironment is acidosis, which results from the local increase in lactic acid production by tumor cells. This phenomenon is attributed to the carbons from glutamine and glucose, which are also used for lactic acid production. Lactic acidosis also directs the metabolic reprogramming of tumor cells and serves as an additional selective pressure. Finally, we also discuss the role of mitochondria in supporting tumor cell metabolism. PMID:22057267

  13. Cell Proliferation in Neuroblastoma

    Directory of Open Access Journals (Sweden)

    Laura L. Stafman

    2016-01-01

    Full Text Available Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed.

  14. Patterning Stem Cell Differentiation

    OpenAIRE

    Vunjak-Novakovic, Gordana

    2008-01-01

    Regulation of cell differentiation and assembly remains a fundamental question in developmental biology. Now, a report from the Chen laboratory (Ruiz and Chen, 2008) describes an approach that represents a major step toward a more profound understanding of the geometric-force control of stem cell differentiation.

  15. Programmed cell death

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

  16. Solar cell concentrating system

    International Nuclear Information System (INIS)

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  17. Electrochemical cell stack assembly

    Science.gov (United States)

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2010-06-22

    Multiple stacks of tubular electrochemical cells having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films arranged in parallel on stamped conductive interconnect sheets or ferrules. The stack allows one or more electrochemical cell to malfunction without disabling the entire stack. Stack efficiency is enhanced through simplified gas manifolding, gas recycling, reduced operating temperature and improved heat distribution.

  18. Modeling: driving fuel cells

    Directory of Open Access Journals (Sweden)

    Michael Francis

    2002-05-01

    Fuel cells were invented in 1839 by Sir William Grove, a Welsh judge and gentleman scientist, as a result of his experiments on the electrolysis of water. To put it simply, fuel cells are electrochemical devices that take hydrogen gas from fuel, combine it with oxygen from the air, and generate electricity and heat, with water as the only by-product.

  19. Dynamics of cell orientation

    Science.gov (United States)

    de, Rumi; Zemel, Assaf; Safran, Samuel A.

    2007-09-01

    Many physiological processes depend on the response of biological cells to mechanical forces generated by the contractile activity of the cell or by external stresses. Using a simple theoretical model that includes the forces due to both the mechanosensitivity of cells and the elasticity of the matrix, we predict the dynamics and orientation of cells in both the absence and presence of applied stresses. The model predicts many features observed in measurements of cellular forces and orientation including the increase with time of the cellular forces in the absence of applied stress and the consequent decrease of the force in the presence of quasi-static stresses. We also explain the puzzling observation of parallel alignment of cells for static and quasi-static stresses and of nearly perpendicular alignment for dynamically varying stresses. In addition, we predict the response of the cellular orientation to a sinusoidally varying applied stress as a function of frequency.

  20. Physics of adherent cells

    Science.gov (United States)

    Schwarz, Ulrich S.; Safran, Samuel A.

    2013-07-01

    One of the most unique physical features of cell adhesion to external surfaces is the active generation of mechanical force at the cell-material interface. This includes pulling forces generated by contractile polymer bundles and networks, and pushing forces generated by the polymerization of polymer networks. These forces are transmitted to the substrate mainly by focal adhesions, which are large, yet highly dynamic adhesion clusters. Tissue cells use these forces to sense the physical properties of their environment and to communicate with each other. The effect of forces is intricately linked to the material properties of cells and their physical environment. Here a review is given of recent progress in our understanding of the role of forces in cell adhesion from the viewpoint of theoretical soft matter physics and in close relation to the relevant experiments.

  1. Fifty cell test facility

    Energy Technology Data Exchange (ETDEWEB)

    Arntzen, J. D.; Kolba, V. M.; Miller, W. E.; Gay, E. C.

    1980-07-01

    This report describes the design of a facility capable of the simultaneous testing of up to 50 high-temperature (400 to 500/sup 0/C) lithium alloy/iron sulfide cells; this facility is located in the Chemical Engineering Division of Argonne National Laboratory (ANL). The emphasis will be on the lifetime testing of cells fabricated by ANL and industrial contractors to acquire statistical data on the performance of cells of various designs. A computer-based data-acquisition system processes the cell performance data generated from the cells on test. The terminals and part of the data-acquisition equipment are housed in an air-conditioned enclosure adjacent to the testing facility; the computer is located remotely.

  2. Cell Control Engineering

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo

    1996-01-01

    The engineering process of creating cell control systems is described, and a Cell Control Engineering (CCE) concept is defined. The purpose is to assist people, representing different disciplines in the organisation, to implement cell controllers by addressing the complexity of having many systems...... in physically and logically different and changing manufacturing environments. The defined CCE concept combines state-of-the-art of commercially available enabling technologies for automation system software development, generic cell control models and guidelines for the complete engineering process....... It facilitates the understanding of the task and structure of cell controllers and uses this knowledge directly in the implementation of the system. By applying generic models CCE facilitates reuse of software components and maintenance of applications. In many enterprises, software makes up an increasing part...

  3. Cell fusions in mammals

    DEFF Research Database (Denmark)

    Larsson, Lars-Inge; Bjerregaard, Bolette; Talts, Jan Fredrik

    2008-01-01

    Cell fusions are important to fertilization, placentation, development of skeletal muscle and bone, calcium homeostasis and the immune defense system. Additionally, cell fusions participate in tissue repair and may be important to cancer development and progression. A large number of factors appear...... to regulate cell fusions, including receptors and ligands, membrane domain organizing proteins, proteases, signaling molecules and fusogenic proteins forming alpha-helical bundles that bring membranes close together. The syncytin family of proteins represent true fusogens and the founding member, syncytin-1......, has been documented to be involved in fusions between placental trophoblasts, between cancer cells and between cancer cells and host ells. We review the literature with emphasis on the syncytin family and propose that syncytins may represent universal fusogens in primates and rodents, which work...

  4. Metallization of bacteria cells

    Institute of Scientific and Technical Information of China (English)

    LI; Xiangfeng; (黎向锋); LI; Yaqin; (李雅芹); CAI; Jun; (蔡军); ZHANG; Deyuan; (张德远)

    2003-01-01

    Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.

  5. Solid electrolytic fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Masayasu; Yamauchi, Yasuhiro; Kamisaka, Mitsuo; Notomi, Kei.

    1989-04-21

    Concerning a solid electrolytic fuel cell with a gas permeable substrate pipe, a fuel electrode installed on this substrate pipe and an air electrode which is laminated on this fuel electrode with the electrolyte in between, the existing fuel cell of this kind uses crystals of CaMnO3, etc. for the material of the air electrode, but its electric resistance is big and in order to avert this, it is necessary to make the film thickness of the air electrode big. However, in such a case, the entry of the air into its inside worsens and the cell performance cannot develop satisfactorily. In view of the above, in order to obtain a high performance solid electrolytic fuel cell which can improve electric conductivity without damaging diffusion rate of the air, this invention proposes with regard to the aforementioned solid electrolytic fuel cell to install a heat resistant and conductive member inside the above air electrode. 6 figs.

  6. Nanoelectrochemistry of mammalian cells.

    Science.gov (United States)

    Sun, Peng; Laforge, François O; Abeyweera, Thushara P; Rotenberg, Susan A; Carpino, James; Mirkin, Michael V

    2008-01-15

    There is a significant current interest in development of new techniques for direct characterization of the intracellular redox state and high-resolution imaging of living cells. We used nanometer-sized amperometric probes in combination with the scanning electrochemical microscope (SECM) to carry out spatially resolved electrochemical experiments in cultured human breast cells. With the tip radius approximately 1,000 times smaller than that of a cell, an electrochemical probe can penetrate a cell and travel inside it without apparent damage to the membrane. The data demonstrate the possibility of measuring the rate of transmembrane charge transport and membrane potential and probing redox properties at the subcellular level. The same experimental setup was used for nanoscale electrochemical imaging of the cell surface. PMID:18178616

  7. Digital Microfluidic Cell Culture.

    Science.gov (United States)

    Ng, Alphonsus H C; Li, Bingyu Betty; Chamberlain, M Dean; Wheeler, Aaron R

    2015-01-01

    Digital microfluidics (DMF) is a droplet-based liquid-handling technology that has recently become popular for cell culture and analysis. In DMF, picoliter- to microliter-sized droplets are manipulated on a planar surface using electric fields, thus enabling software-reconfigurable operations on individual droplets, such as move, merge, split, and dispense from reservoirs. Using this technique, multistep cell-based processes can be carried out using simple and compact instrumentation, making DMF an attractive platform for eventual integration into routine biology workflows. In this review, we summarize the state-of-the-art in DMF cell culture, and describe design considerations, types of DMF cell culture, and cell-based applications of DMF. PMID:26643019

  8. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  9. PEM regenerative fuel cells

    Science.gov (United States)

    Swette, Larry L.; Laconti, Anthony B.; McCatty, Stephen A.

    1993-11-01

    This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi); in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations.

  10. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  11. Advances in stem cell research

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@In 1998, biologists Thomson and Gearhart successfully derived stem cells from human embryos. One year later, several researchers discovered that adult stem cells still retain the ability to be differentiated into unrelated types of cells. Advances in stem cell research open a promising direction for applied medical science. Moreover, it may also force scientists to reconsider the fundamental theory about how cells grow up. Stem cell research was considered by Science as the top of the ten breakthroughs of science of the year[1]. This paper gives a survey of recent advances in stem cell research. 1 Overview In the 1980s, embryonic stem cell and/or embryonic germ cell line (ES cell line, EG cell line) of multifarious mammalian animals, especially those of non-human pri-mates, had been established. In 1998, Thomson and Shamblott obtained ES, EG cell lines from human blasto-cysts and gonad ridges of early human embryos, respec-tively. Their research brought up an ethical debate about whether human embryos can be used as experimental materials. It was not appeased until 1999 when research-ers discovered that stem cells from adults still retain the ability to become different kinds of tissue cells. For in-stance, brain cells can become blood cells[2], and cells from bone marrow can become cells in liver. Scientists believe, for a long time, that cells can only be developed from early pluripotent embryo cells; the differentiation potential of stem cells from mature tissues is restricted to only one of the cell types of the tissue where stem cells are obtained. Recent stem cell researches, however, sub-verted the traditional view of stem cells. These discoveries made scientists speed ahead with the work on adult stem cells, hoping to discover whether their promise will rival that of ES cells.

  12. Langerhans' cells, veiled cells, and interdigitating cells in the mouse recognized by a monoclonal antibody

    OpenAIRE

    1986-01-01

    An mAb, NLDC-145, is described that specifically reacts with a group of nonlymphoid dendritic cells including Langerhans cells (LC), veiled cells (VC), and interdigitating cells (IDC). The antibody does not react with precursor cells in bone marrow and blood. Macrophages are not stained by the antibody, but a subpopulation of Ia+ peritoneal exudate cells is recognized. Possible relationships of the various nonlymphoid dendritic cell (NLDC) types are discussed.

  13. From Adult Bone Marrow Cells to Other Cell Lineages:Transdifferentiation or Cells Fusion

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Recent studies have demonstrated that intravenous transplantation or local injection of bone marrow cells can induce unexpected changes of their fate. The results of these experiments showed that after transplantation or injecton, some of tissue specific somatic cells such as hepatocytes, skeleton, cardiac muscle cells and brain cells expressed the donor cell-specific genes, such as Y chromosome. There are two hypotheses that can explain this phenomenon. One is bone marrow stem cell transdifferentiation and the other is spontaneous cell fusion.

  14. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation

    OpenAIRE

    Stefania Bruno; Cristina Grange; Marta Tapparo; Chiara Pasquino; Renato Romagnoli; Ennia Dametto; Antonio Amoroso; Ciro Tetta; Giovanni Camussi

    2016-01-01

    Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell co...

  15. Genome-Wide Transcriptional Analysis of Differentially Expressed Genes in Diabetic, Healing Corneal Epithelial Cells: Hyperglycemia-Suppressed TGFβ3 Expression Contributes to the Delay of Epithelial Wound Healing in Diabetic Corneas

    OpenAIRE

    Bettahi, Ilham; Sun, Haijing; Gao, Nan; Wang, Feng; Mi, Xiaofan; Chen, Weiping; Liu, Zuguo; Yu, Fu-Shin X.

    2014-01-01

    Patients with diabetes mellitus (DM) may develop corneal complications and delayed wound healing. The aims of this study are to characterize the molecular signatures and biological pathways leading to delayed epithelial wound healing and to delineate the involvement of TGFβ3 therein. Genome-wide cDNA microarray analysis revealed 1,888 differentially expressed genes in the healing epithelia of normal (NL) versus type 1 DM rat corneas. Gene ontology and enrichment analyses indicated TGFβ signal...

  16. Diffusion inside living human cells

    DEFF Research Database (Denmark)

    Leijnse, N.; Jeon, J. -H.; Loft, Steffen;

    2012-01-01

    cells. For these cells the exact diffusional pattern of a particular granule depends on the physiological state of the cell and on the localization of the granule within the cytoplasm. Granules located close to the actin rich periphery of the cell move less than those located towards to the center...... of the cell or within the nucleus. Also, granules in cells which are stressed by intense laser illumination or which have attached to a surface for a long period of time move in a more restricted fashion than those within healthy cells. For granules diffusing in healthy cells, in regions away from the cell...

  17. Langerhans cell histiocytosis of the temporal bone in a child

    OpenAIRE

    Chakravarti, A; Rajeev Gupta; Sahni, J. K.

    2011-01-01

    Langerhans cell histiocytosis of temporal bone is a benign tumor like condition with variable clinical course. This rare clinical entity may mimic common ENT clinical condition like otitis media , mastoiditis and otitis externa . A high index of suspicion is required to reach to a diagnosis of langerhans cell histiocytosis to prevent delay in proper management of this disease.

  18. Many facets of stem cells

    Institute of Scientific and Technical Information of China (English)

    Jiarui Wu

    2011-01-01

    @@ Research area on stem cells is one of frontiers in biology.The collection of five research articles in this issue aims to cover timely developments in stem cell biology, ranging from generating and identifying stem cell line to manipulating stem cells, and from basic mechanism analysis to applied medical potential.These papers reflect the various research tasks in stem cell biology.

  19. Microfluidics for single cell analysis

    DEFF Research Database (Denmark)

    Jensen, Marie Pødenphant

    Isolation and manipulation of single cells have gained an increasing interest from researchers because of the heterogeneity of cells from the same cell culture. Single cell analysis can ensure a better understanding of differences between individual cells and potentially solve a variety of clinic...

  20. Oscillating Cell Culture Bioreactor

    Science.gov (United States)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid